An overview of the development of teenagers with Down syndrome (11-16 years)


I. Development during teenage years

What do typically developing teenagers achieve?

Independence from the family

It is possible to characterise the main developmental changes during teenage years as progress from dependence to independence and we have attempted to illustrate this in Figure 1. Most typically developing 11 year olds still need a high degree of support for all aspects of their daily lives, including personal daily care activities such as bathing, care of clothes, cleaning rooms and preparation of meals, travel and choice of social activities outside the home, and responsibility for money. By the end of the teenage period, most young people will be largely independent of their families. Many will be at work and others will be studying away from home; some will have their own homes. Almost everyone will be able to take care of all their personal daily care needs, laundry, shopping and cooking. Many will be living in their own home, some with partners by this age. Most will be managing their own money. Some will be driving and have a car of their own. This level of competence and independence also implies that most young people are able to behave in a socially appropriate and law-abiding manner, managing their emotions and behaviour appropriately in public, coping with the inevitable temptations of alcohol, smoking and drugs and are able to make and sustain friendships and relationships. In summary most young people are largely independent of their families by the time they reach 20 years of age even though emotional ties, social and financial support and advice from families will still be important.

 An overview of developmental progress during adolescence

Figure 1. An overview of developmental progress during adolescence

A personal identity, friends and relationships

The teenage years are also a very important life period for establishing one's own personal identity. Teenagers discover their skills and aptitudes and make choices about future work and adult roles in society. They discover their personal values, styles of dress and preferred lifestyles, their choices of music, art and leisure activities. Teenagers also experience rapid growth and changes in body and facial appearance - attractiveness can become a big issue. They experience new emotions, puberty, sexuality and find special friends and sexual partners. All these aspects of teenage experience contribute to an individual's identity - how they see themselves - and to their self-confidence and self-esteem. Friends are a very important part of the teenage years, providing support and understanding through this often difficult time as teenagers become increasing self aware and experience self doubts. Adult role models for occupations and for lifestyles also play an important part in the teenager's development.

Cognitive and academic progress, preparations for work

Most teenagers make significant academic progress during their teenage years. All teenagers continue their education for some years - compulsory education continues to 16 years in the UK. Many continue their education and training in colleges or universities into their early adult lives. In the UK education to 19 years is supported for all young people in schools and further education colleges. After this age, many adult education and training opportunities are available through adult education colleges. During the teenage years, young people usually continue to develop their speech, language, literacy and numeracy skills and they expand their knowledge across many general curriculum subjects as well as subjects of their own particular choice. Young people increasingly specialise and choose to gain knowledge and skills in areas that they are interested in and for which they have an aptitude. The later years in education are usually a preparation for work roles in adult life.

What goals should we set for teenagers with Down syndrome?

In the authors' view, based on their experience of working with many teenagers and adults, and as parents, the goals for teenagers with Down syndrome should be essentially the same as those for typically developing teenagers i.e.:

  • to become as independent as possible in their personal care and their social lives
  • to develop a positive personal identity, self-confidence and self-esteem - to feel good about themselves
  • to develop a network of friends, personal relationships and leisure interests
  • to progress their cognitive, speech and language, and academic skills, and prepare for work

Independence and social competence

Parents and teachers need to encourage young people with Down syndrome to become as independent as possible in all areas of their lives. The young person's practical and social independence will increase their privacy and dignity as a person in teenage and adult years. It will also ensure that each individual develops all the skills that he or she is capable of and that each individual has a sense of control over their lives. Research has shown that any individual who feels helpless and who feels that he or she has no control over his or her life is vulnerable to depression and unhappiness. Those working with adults with Down syndrome have reported that the same factors affect the well-being and mental health of adults with Down syndrome.[4]

Social competence is an important part of being able to be independent. Social competence requires the ability to manage one's own behaviour and emotions in an age appropriate manner, the ability to interact appropriately with others in social situations such as in shops, restaurants or buses, and to make and sustain friendships.

Personal identity

All parents hope that their children will feel good about themselves - that they will develop a positive sense of who they are and their place in the world. This process may be more difficult for a teenager with Down syndrome and it is during their teenage years that young people with Down syndrome become more aware of the reality of their disability and the limits that this is going to place on their adult lives. It is not unusual for teenagers to show their distress as they see younger brothers and sisters going out alone, having boyfriends or girlfriends, learning to drive the car and then leaving home to start families of their own.

Many teenagers with Down syndrome do not have sufficient language ability to be able to express what they are feeling to family or friends and this can be a difficult time. In the authors' experience, some teenagers with Down syndrome may express their distress by becoming withdrawn or unco-operative, by having uncharacteristic outbursts off difficult or aggressive behaviour or by becoming clinically depressed. The majority of these young people come through this period and adjust to adult life but some will need professional support and treatment. Most teenagers with Down syndrome cope with adjusting to the pressures of adolescence without any outward signs of distress but this does not mean that the adjustment has not been painful for them at times.

Families need to be sensitive and not underestimate the young person's awareness of the issues because they cannot express them. It may help to have friends with Down syndrome or a similar level of learning disability. In times of stress, most of us find support in having friends who been through the same experiences and can empathise with what we are experiencing. It may also help if positive adult role models - adults with Down syndrome who are enjoying their lives - can be found in the teenager's own community. Videos are available, made by adults with Down syndrome with this need in mind, and they may prove helpful.[5,6] The reader may also find it useful to refer again to the views of adults with Down syndrome in the Living with Down syndrome module.[DSii-01-01] The degree to which a young person has some control over their lives and the choices they can make will also influence their adjustment. It is important to respect the right of the teenager to be treated in a chronologically appropriate way, and to try to avoid treating him/her as if he/she is younger.

Friends and social lives

Research into the mental health of all adults identifies the importance of networks for friendship and social support. Loneliness and social isolation increase vulnerability to misery and mental health problems. Friendships which provide mutual respect, understanding and emotional support become particularly important for young people during adolescence. Schools, social activities and clubs all provide the opportunity to make friends. However, teenagers with Down syndrome may be more dependent on the support of others to ensure that they actually go to leisure activities and clubs where they can make friends.

For teenagers in special education, it may be difficult to meet with school friends out of school as families may live too far from each other and the teenagers may not have independent travel skills. For teenagers in inclusive school settings, the friendships with non-disabled peers are different in that they are 'helping' friendships rather than mutually supportive, reciprocal friendships, and they may not continue out of school. The teenagers included in mainstream schools may not have enough opportunities to meet other teenagers with Down syndrome or a similar level of learning disability to establish friendships and parents may need to take active steps to create these opportunities out of school. Research discussed elsewhere in this module (see 'A more detailed look' and 'Social and interpersonal development') suggests that this is an issue which needs to be addressed.

Cognitive and academic progress

Research indicates that most teenagers with Down syndrome make significant progress in cognitive and academic skills and that the development of basic literacy and numeracy skills should be a priority during teenage years. Some teenagers will start their secondary education with significant reading and writing skills (at about an 8 year level) and some will have basic numeracy to a 6 to 7 year level, but many teenagers will start secondary school with minimal literacy and numeracy skills (5 to 6 year level) and develop these skills to a level of functional usefulness during their teenage years. Indeed, some observers suggest that many teenagers are ready to make progress because their general cognitive skills are sufficiently advanced and they are motivated to learn because they are now old enough to see the practical value of these skills in their daily lives.[7,8] They want to be able to read names, notices, messages and instructions and they want to understand and use money. For this reason, the modules on reading and number for 11-16 year olds in this series take a basic skills approach to teaching these skills and provide activities to take teenagers from the earliest stages to more advanced levels. There are no real short cuts to real understanding and competence in literacy or numeracy - the basic steps need to be understood before more advanced progress is possible - though there are short cuts to functional use which do not require full understanding and these are also included in the practical modules. However, parents and teachers are encouraged not to assume that teenagers will not understand the basics and therefore to opt for the functional approach too quickly, but to continue to give teenagers the opportunity to understand the basics.

Research also indicates that many teenagers make significant progress in speech and language during the teenage years so that this is also identified as a priority for parents, teachers and speech and language therapists. Many speech and language activities can be readily linked into the school curriculum and parents can also work on them during daily activities at home.

The whole range of targets that the authors believe to be priorities for teenagers with Down syndrome are summarised in Figure 2. The range of achievements which might be expected for each of these areas of development is summarised below (see 'What levels of achievement can we expect?'. Before reviewing these expectations in detail, in the next section general trends and some important influences on teenagers' development are considered, based on the authors' research studies.

An overview of developmental progress from eleven to sixteen years in children with Down syndrome

Figure 2. An overview of developmental progress from eleven to sixteen years in children with Down syndrome

Major trends in development

There is a very wide range of variation in the rates of progress of teenagers with Down syndrome. The authors have conducted two in-depth studies of the development of teenagers with Down syndrome, aged from 11-20 years, and the detailed information on the range of skills achieved is included in the practical modules in this series for the guidance of parents and teachers. For example, the specific information on the range of achievements in reading and writing is included in the reading module, on number, time and money in the number modules and on speech and language skills in the speech and language module. The detailed information on practical self-help skills and social behaviour is in the social module. The information on health, puberty and sexuality is discussed in the health section of this module.

In this section, an overview of the findings is presented as they illustrate important progression with age for almost every skill measured and also some strengths and weaknesses in specific areas of development. The data also allows the progress of teenagers who have been included in mainstream schooling for the whole of their education to be compared with the progress of teenagers who have been in special education settings. The authors conducted surveys of teenagers with Down syndrome in the same county in the UK in 1987 and in 1999. This has enabled them to compare the progress of two different cohorts of teenagers to see if there has been any improvement in educational or social outcomes as a result of changes in social attitudes and expectation and improvements in educational opportunities over the 12 year period. In 1987, the authors collected information on 90 teenagers in the county of Hampshire, UK.[3] At this time they were all being educated in special schools for children with severe learning difficulties.

In 1999, the authors and colleagues collected information on the progress of 46 teenagers in the same county, where the full inclusion of children with Down syndrome into local mainstream schools from 5 years of age began in one part of the county in 1988. This inclusion project was supported by charitable funding and inclusion did not begin at the same time in the rest of the county. This has enabled a comparative study of the progress of teenagers with Down syndrome, of similar abilities and family backgrounds, placed in full inclusion or in special schools, purely on the basis of where they lived. This study is reported in full elsewhere,[1,2] but it is important to note that the teenagers in the two groups do not vary on any significant family or social variables which might affect their progress.

See also:

  • An overview of less typical developmental issues in Down syndrome

In 1999, data was originally collected from 28 teenagers in special schools but to try to ensure that we were comparing young people of potentially similar abilities, the 5 'least able' teenagers from the special schools were taken out of the comparison group, before these figures were calculated and compared. These 5 'least able' teenagers are those with significantly more developmental delay and health problems than the rest of the group. Two of them have autism in addition to Down syndrome and three of the five have significantly high rates of difficult behaviours. These young people have had multiple difficulties since childhood, and children with this level of difficulty would not have been placed in mainstream classes in any part of the county at the time of the study. In the view of the authors, the needs of this group and their families are significantly different from those of the majority of teenagers with Down syndrome, and this issue is addressed in more detail below (see 'Teenagers with more severe developmental delays'). The average age of the mainstream group is also two years younger than the average age of the special school group, which would reduce the likelihood of finding higher scores on any measures for the total mainstream group.

It is also important to note that the teenagers in the mainstream schools have been fully included in age-appropriate classes in their local schools, supported by a Learning Support Assistant for the majority of the day. They have not been in special classes or resource rooms in mainstream schools and, usually, they have been the only child with Down syndrome or a similar level of learning difficulty in school until they reached secondary schools. In secondary school some have continued to be the only teenager with Down syndrome, but some have been with one or two others with Down syndrome in school.

Many of the results of the study were not as the researchers might have predicted and the findings raise some important issues for parents and educators of teenagers with Down syndrome to consider and to address.

In both 1987 and 1999, the information was collected by surveys. In both studies, parents completed a questionnaire designed by the authors, the Sacks & Buckley Questionnaire (SBQ). In the second study, additional standardised questionnaires were also used, the Vineland Adaptive Behaviour Scale (VABS)[9] and the Conners Rating Scales (CRS).[10] The two main questionnaires (the SBQ and VABS) both contain measures of personal independence skills - Daily Living Skills - which include measures of skills in dressing, toileting, bathing, cleaning, laundry and meal preparation, also time, money, telephone use and road safety. They also both contain measures of speech, language and literacy skills - Communication Skills, and measures of friendship, leisure and social skills - Socialisation Skills. The Vineland Adaptive Behaviour Scale provides normative data which allows scores achieved on the scales to be translated into age equivalent scores. This is useful because it allows us to compare the progress of the teenagers in different aspects of their development. We would expect progress to be even for most individuals, that is, that all skills will be at approximately the same age-level. The age equivalent score also allow us to identify the extent of progress with age and this is illustrated in the first set of histograms in Figure 3.

Progress with age for Daily Living Skills, Socialisation and Communication Skills

Figure 3. Progress with age for Daily Living Skills, Socialisation and Communication Skills (group means for Vineland Age Equivalent Scores)

Progress with age

These findings are presented separately for the teenagers in mainstream and special schools, as some interesting and important similarities and differences which are of practical significance emerge as we consider the findings.

The first two histograms in Figure 3 indicate that Daily Living Skills and Socialisation Skills can be expected to improve significantly as young people with Down syndrome progress through their teens (though with the caution that these figures are for different teenagers in each age group not the same teenagers as they get older). However, as we also demonstrated progression with age on all measures in the 1987 study, we are confident that the majority of young people with Down syndrome will progress their skills during their teenage years. When we look at the third histogram in Figure 3, for Communication Skills, we see significant progress for the oldest group of mainstreamed teenagers but no significant progress with age for the teenagers in special education. These differences in progress in speech, language and literacy will explored in more detail in the next section.

The first important conclusion we can draw from this piece of research is that we can expect significant progress in all areas of development during teenage years. There is no evidence for a 'plateau' being reached, or even a slowing of progress.

The reader will also have observed that there are no significant overall differences in the Daily Living Skills or Socialisation Skills of the teenagers educated in special or mainstream schools, though there is a difference on one measure which contributes to the Socialisation Skills score - the Interpersonal Relationships Scale. This difference may be important and is discussed in more detail in the next section and later in the module (see 'Social and interpersonal development').

A more detailed look

For each main scale on the VABS there are 3 subscales which contribute to that score and the information for these subscales is illustrated in Figure 4. The first histogram illustrates that for Daily Living Skills the teenagers were performing at a similar level in personal and practical skills in the domestic (e.g. preparing meals, cleaning, taking care of laundry), personal (e.g. independence in toileting, bathing, dressing) and community (e.g. staying at home alone, time, money, telephone and road skills) areas. It also illustrates that there were no significant differences in outcomes for the teenagers from the mainstream or the special schools.

The relationships between the subscales for Daily Living, Socialisation and Communication skills

Figure 4. The relationships between the subscales for Daily Living, Socialisation and Communication skills (group means for Vineland Age Equivalent Scores)

The second histogram, however, illustrates that for the Socialisation Skills measure there is a difference on the subscales for the interpersonal relationships subscale, which covers social interaction, dating and friendship skills. There were no differences on the play and leisure (going to clubs, games, hobbies, leisure activities) or on the coping skills (awareness of manners, social sensitivity and social rules) subscales.

On the interpersonal relationships subscale, the teenagers educated in the special schools scored significantly higher, largely due to differences in scores for the oldest of the age groups. This was the only measure of the many measure used in this research which showed a significantly better outcome for teenagers in special education. The numbers of teenagers in the study are quite small - 18 in mainstream education and 23 in special education - so that further research is needed to explore any significance of this finding further. However, one possibility is that the teenagers in special education have had more opportunity to develop mutually supportive, reciprocal friendships with peers of similar abilities and interests than those included in mainstream schools.

The third histogram in Figure 4 illustrates the results for the three subscales in the Communication Skills score. For the teenagers in mainstream schools, the results indicate that their receptive and expressive language is progressing at the same rate and that reading and writing is a specific strength and better than might be predicted from their other language abilities. For the teenagers in special education, their receptive language is at a similar level to those in mainstream school but their expressive language is, in fact, developmentally 3 years behind their receptive language. Their reading and writing abilities are at the same level as their receptive language but significantly behind the reading and writing skills of the mainstreamed teenagers (by approximately 3 years).

It is possible that the improved expressive language of the teenagers in mainstream schools is linked to their reading and writing progress. Researchers suggest that expressive skills are delayed by hearing, speech motor difficulties, auditory memory and auditory processing difficulties.[11,12,13] Therefore, written language may well be easier for young people with Down syndrome to access and to learn vocabulary and grammar from than spoken language. In addition, phonics work plus reading practice may improve speech-motor production skills and speech intelligibility.

The teenagers being educated in mainstream classrooms, with the individual help of a Learning Support Assistant, will have received daily literacy teaching with their typically developing peers. They will also have recorded their learning in all lessons by writing it down and reading it - with whatever level of support was needed. The level of engagement in literacy activities will have been much greater than that experienced in the special school classrooms.

Overall profiles

In Figure 5 the histograms show the overall results for the main developmental areas - Daily Living, Socialisation and Communication Skills. For the teenagers in the mainstream schools there are no significant differences in the progress being made in each of these areas of development. Communication Skills are good, largely due to their progress with expressive language and literacy. For the teenagers in the special schools, their Communication Skills are significantly delayed relative to their Daily Living and Socialisation skills.

The relationship between the three aspects of development, Daily Living, Communication and Socialisation

Figure 5. The relationship between the three aspects of development, Daily Living, Communication and Socialisation (group means for Vineland Age Equivalent Scores)

This special school profile is, in fact, the one that researchers would expect to see for teenagers with Down syndrome. A number of studies have found that speech and language skills, particularly expressive skills are specifically delayed relative to both non-verbal cognitive abilities and to social and independence skills.[13,14]

The results of the current research with the Hampshire teenagers suggests that it is possible to remediate the speech and language difficulties and to bring expressive language abilities in line with receptive language for teenagers with Down syndrome. The results indicate that a major factor may be the development of reading and writing and the use of literacy activities to teach and to support spoken language development.

Another major factor may be that the mainstreamed teenagers have been surrounded by typically developing competent spoken language users since they entered preschools at 3 years of age and this spoken language and communication environment will have been very different to that experienced by the teenagers in the special schools. Almost all of the special school group have been in special schools for children with severe learning difficulties for their entire school career and this means that they have been with children the majority of whom have very significantly impaired language.

Personality and behaviour

Another major area of developmental importance that was looked at in these Hampshire teenage studies was the extent of behaviour difficulties, whether any behaviour difficulties change with age and if school placement has any influence on behaviour. In the authors' experience, behaviour can be an important issue in teenage and adult years for some individuals.

Significantly difficult behaviour affects the learning and social opportunities of a teenager with Down syndrome and can create considerable stress for teachers and for families. Conversely, teenagers who can behave in a socially acceptable and competent manner will be more likely to have friends, to have active social lives and to be successful in work as adults, than those who do not.

In the authors' experience, socially confident and acceptable behaviour can be more important in determining quality of life for adults than academic achievements. Of course, both contribute to increasing the range of opportunities and independence open to adults, but skills and abilities without behaviour control will not lead to a happy life. This is equally true, of course, for non-disabled teenagers and adults.

Difficult behaviours need to be considered in relation to the helpful and socially sensitive behaviour and the positive personalities that are characteristic of most teenagers with Down syndrome. Many references to the positive aspects of teenagers personalities were made by parents during the recent Hampshire survey, for example:-

''J is a happy and content girl, very understanding, helpful and has a great personality - she brings out the best in everyone.''

''He is happy and outgoing and lots of people know him so we talk to more people because of him.''

''She is a wonderful, happy and most loved member of our family. She is kind, caring, happy and thoughtful.''

''A has a positive approach to life and brings that to the family. His caring nature and enthusiasm are infectious. I think he has made the family dynamics easier than they would have been, especially teenage years.''

''She is good company, always happy, funny and content''

''Good point is he is a happy lad who is good fun and has taught us a lot''.

''Very loving, trusting and happy boy - enjoys life and is very sociable.''

''Our daughter brings more love, fun and laughter to family life and though she will never be 'academic' there are other qualities she has which cannot be measured.''

''He is popular, friendly and non-judgemental-he has added another dimension to our lives''.

''Brings a lot of happiness to our lives. Her disruptiveness - being rude or awkward - can cause parents and sister to get cross and upset''

The last quote highlights the fact that difficult behaviours occur only sometimes and do not define the person's character. Someone with a positive personality can be difficult at times and this would characterise most of the teenagers in the survey. However, this does not mean the difficult behaviours are not distressing when they do occur and most parents are pleased to obtain advice on how to handle them.

Several measures were used to collect information about any behaviour difficulties that the teenagers had. There were behaviour questions on the original Sacks and Buckley Questionnaire[3] and a Maladaptive Behaviour Scale on the Vineland Adaptive Behaviour Scales.[9] In addition, the Conners Behaviour Rating Scale[10] provides measures of several different aspects of behavioural difficulties, hyperactivity, cognitive problems or inattention, oppositional behaviour and Attention Deficit/Hyperactivity Disorder-ADHD.

All the measures illustrated that difficult behaviours tend to improve with age for most individuals, with only one teenager over 18 years in the main schools comparison group having even a moderate level of difficulties. This strongly suggests that many of the behaviours reported for the younger teenagers may be linked to general cognitive delays and immaturity.

There was only one measure on which the teenagers from the different school systems scored significantly differently - The VABS Maladaptive Behaviour Scale - and these results are illustrated in Figure 6. The scores can be classified in terms of the severity of the behaviour difficulties. As the data below shows, significant behaviour difficulties only affect a minority. The teenagers in the mainstream schools were less likely to have difficulties, with 63% having no significant difficulties compared with 41% in the special schools, 25% having a moderate level of difficulties compared with 27% in the special schools and 12% (one in eight) having significant behaviour difficulties compared with 32% (one in three) in special schools.

The significance of reported behaviour difficulties

Figure 6. The significance of reported behaviour difficulties (percentage of teenagers in each category)

The reader is reminded that the 5 'least able' teenagers in the special schools are not included in this comparison. Three of these 5 had very high scores for difficult behaviours and the remaining 2 had low scores.

This means that in the whole sample of teenagers, and the whole sample is representative of all teenagers with Down syndrome, 26% (one in four) have some significant behaviour difficulties which will be probably causing problems at home and at school on a daily basis.

The Vineland Maladaptive Behaviour Scale predominantly includes questions about two main types of behaviour, those that may reflect anxiety and nervousness and those that reflect conduct disorder and poor attention.

On the specific Conners Behaviour measures which focus on conduct disorders and attention difficulties, there were no significant differences between the levels of difficulties for the teenagers in mainstream or special schools. When the scores of the teenagers with Down syndrome are compared with norms for typically developing teenagers, the proportion of the total group who had serious difficulties was 16% on each of the Oppositional Behaviour, the Cognitive problems/inattention and the ADHD measure and 37% on the Hyperactivity measure. (The reader should note that some 5% of the regular population of teenagers of the same age will score in the serious difficulties range as defined by the Conners Scales). Some behaviours may reflect immaturity and improve with age.

The hyperactivity measures include, being always 'on the go', hard to control while shopping, runs about or climbs excessively in situations where it is inappropriate, restless in the squirmy sense, has difficulty waiting in line or taking turns, has difficulty playing or engaging in leisure activities quietly. The high score here may reflect immaturity for age. Similar findings have been reported by other researchers and interpreted in this way.[15,16]

For example, in another UK research study which included four groups, children and teenagers with Down syndrome, their brothers and sisters, other children with learning disabilities and typically developing children, the hyperactivity score of the 16-19 year olds with Down syndrome was the same as that of the typically developing group whose mean age was 9 years 4 months and included 4 to 15 year olds. In this study the behaviour rating scores all significantly and steadily declined with age from 4 to 19 years for the children and teenagers with Down syndrome.[16]

Behaviour is good relative to cognitive abilities

See also:

  • Strategies for changing behaviour and developing social skills for individuals with Down syndrome

As reported in other studies, all the behaviour scores for the group with Down syndrome were significantly lower than those for the children with a similar level of learning difficulties but not Down syndrome, but tended to be higher than the scores of the two non-disabled groups, brothers and sisters of those with Down syndrome and a typically developing group from the general population.[16] Readers may be interested to know that the behaviour scores of the brothers and sisters of children and teenagers with Down syndrome were no different from those of children from the general population who did not have a disabled brother or sister. Therefore, there was no evidence of adverse effects of growing up with a sibling with Down syndrome.

See also:

Some researchers report that more boys than girls have difficult behaviour but in the authors' study there were no differences between boys and girls, in either the mainstream or special school groups, on any of the measures and an Australian study also found no general differences.[17]

The link between behaviour and poor communication skills

Similar to other studies, and the authors' 1986 study, there was a significant relationship between expressive communication skills and behaviour difficulties - the more limited a teenager's expressive language ability, the more likely he or she is to have behaviour difficulties. The implication here is that at least some difficult behaviours are the teenager's way of communicating when he/she does not have the language to do so. In addition, some behaviours may be the result of the frustration that arises when an individual is not understood.

Difficult behaviour is stressful for families

Many studies report a link between family stress and the level of difficult behaviours, with mothers often particularly affected.[18-20] Therefore, while only a minority of teenagers with Down syndrome can be described as difficult, it is important that the needs of these young people and their families are recognised. Many, if not most, difficult behaviours can be changed but not always easily or quickly. More persistent difficult behaviours will be more difficult to change and families and teachers will benefit from the support of professionals skilled in behaviour management.

Behaviour difficulties can arise for a variety of reasons and, because of the effects that they have on the life of affected teenagers, there is a practical module for this age group which discusses causes and management approaches for difficult behaviours in depth.

In summary

In summary, when we look at the main trends in the data we see:

  • steady progress with age, and no evidence of a plateau in any area of development.
  • progress in independence in daily living skills and in social skills - and no significant difference in progress for these in mainstream or special education settings, perhaps because a major influence on progress in these areas of development is the learning opportunities and expectations of the family.
  • significantly greater delay in expressive communication skills when compared with progress in daily living and social skills for the teenagers educated in special schools.
  • no significant delay in expressive communication skills for the teenagers educated in mainstream schools. This means that the teenagers in mainstream schools have significantly better spoken language and literacy skills than their similar ability peers in special education. They also have significantly better numeracy skills. The main benefit of inclusive education of the type experienced by these teenagers has been in spoken language and academic progress.
  • while general social and social independence skills did not vary between the two groups, the teenagers in special schools had significantly better interpersonal friendship skills, and the importance of this finding and some of the reasons for it are discussed more fully in the next section.
  • the majority of parents described the positive personalities of their teenagers, their social sensitivity, and how much they contributed to family life. However, about 16% of teenagers do exhibit difficult behaviours at times, and about one third show some immature behaviour for their age (but probably not immature for their cognitive and communication abilities at this time). Most teenagers will grow out of these behaviours by their late teens.
  • a small number of teenagers do show persistent difficult behaviours, and this reduces their social and learning opportunities as well as increasing the stress experienced by their families.
  • about 10% of any population of individuals with Down syndrome can be expected to have profound and multiple disabilities. Life for these teenagers and their families is rather different than for the rest of the population. They are still highly dependent and their educational and support needs are different. Parents of these teenagers frequently express the view that their needs are not understood, especially by those representing the majority of individuals with Down syndrome, such as Down syndrome associations, and by those campaigning for inclusive education. The needs of these individuals is explored in more detail below (see 'Teenagers with more severe developmental delays') and in a separate DSii module An overview of less typical developmental issues in Down syndrome.[DSii-01-09]

What levels of achievement can we expect?

The previous section has identified some of the main trends in achievements and factors which may influence them, but does not give the reader an idea of the actual skills that teenagers with Down syndrome may have in each area of development or the range of individual differences. Taking each of the headings in Figure 2 the range of expected achievements are summarised in this section, based on the Hampshire surveys of representative groups of teenagers.

Personal care and daily living skills

Personal care and hygiene

Most teenagers with Down syndrome are well on the way to personal independence and privacy in the area of self care. Almost all teenagers (some 85%) can dress and undress without assistance and manage most fastenings. A similar number can choose and find their own clothes each day and some 70% can choose appropriate clothes for the weather. Most teenagers (some 85%) choose their own new clothes and show a preference for fashion styles.

However, only about half the group are completely independent when we consider personal hygiene as, while 92% can wash in the bath unaided and some 80% dry themselves unaided, only half of the teenagers can run a bath without help, only a third could wash their hair without help and only 10% could cut their own nails. Almost everyone was fully continent day and night (95%) and could go to the toilet without a prompt. However while some 90% could manage their clothing unaided in the toilet, 25% were still receiving assistance to wipe themselves, and 20% did not flush the toilet. While 65% washed their own hands without help, 20% did not - this means that some 25% of the teenagers still needed assistance in the toilet.

Almost everyone could clean their teeth and brush their hair unaided, but less than half actually did brush their hair daily without help, presumably because parents felt that they could improve their teenager's appearance if they still helped. This raises the issue of encouraging independence. Parents need to be very aware of the importance of being independent for self-esteem and personal growth. It is not easy to let go and to accept that, while teenagers are learning to be competent they will not make as good a job of the tasks as when parents do them, but they will only reach a good level of competence if allowed to try for themselves.

It is easy to continue to provide help for 11 and 12 year olds without considering what is age-appropriate and the need to begin to encourage independence and privacy. Most teenagers with Down syndrome will need more practice to become competent and therefore this should start early. The shower is often easier to manage than the bath, especially for washing hair and rinsing it adequately. Nail clippers are easier to learn to use than scissors, and learning to be fully independent in the toilet takes time and practice.

In each area, teenagers need to begin to take over the tasks over a period of time, with parents teaching them how to do the tasks rather than doing them for them.

Mealtimes and cooking

Almost all teenagers (95%) could eat and drink completely independently though some 30% still needed assistance with cutting up food. Almost everyone (95%) could serve themselves from serving dishes on the table and 90% could help themselves to salt, pepper and sauces. Everyone could be taken out to eat in a restaurant. When it comes to making meals and snacks, everyone could help themselves to a biscuit, 95% could get a glass of water, some 64% could make squash and 82% could get a glass of milk without assistance. Half of the teenagers could make a sandwich, a piece of toast and a cup of tea or coffee. About a third of the teenagers could use a can opener, about 25% could use the microwave oven and only 10% could use the grill or the oven. In other words, beyond simple snacks, most teenagers could not prepare or cook a meal. However, most of them (80%) could lay and clear the table and about half could wash and dry the crockery.

Learning to prepare and cook meals involves taking risks, using knives, hot pans, boiling water, grills, open gas or electric rings and hot ovens. However, in later teens, some young people become very skilled in cooking and many take catering courses. Like learning to carry out all personal hygiene tasks, teenagers will only learn to cook safely if they are able to learn the necessary skills, in small steps and with supervision.

Independence and responsibility in the home

Most teenagers (86%) had their own bedroom and 65% - 70% took a pride in their room and kept it tidy. Almost all (90%) put up their own pictures and posters. Some 14% of teenagers helped with household chores. However, in terms of being able to be left alone at home, about a third of teenagers could be safely left for short periods of time but only 7% for longer periods.

See also:

  • Social development for teenagers with Down syndrome (11-16 years)

Most teenagers had the privacy of a room of their own, and were beginning to take some responsibility for tidying. We did not ask about doing the laundry or ironing, but most teenagers should be encouraged to learn all the domestic tasks which will enable them to care for their own rooms, laundry and shared areas in the house as they approach adulthood.

The main reasons that parents give for not leaving teenagers alone for long is their limited ability to deal with the unexpected. Most teenagers could be trusted not to do anything inappropriate or dangerous if left alone, but most teenagers could not yet use the telephone independently to call for help in an emergency. Some families were extending the time the teenager could be left alone in the house by enlisting the help of neighbours. If a neighbour is at home, the teenager can go to them for help if it is needed.

Social independence outside the home

Of the mainstream teenagers, 22% could go to a local shop alone, 83% had pocket money, 44% could cross roads alone and only one teenager walked to the school bus alone. Of the special school teenagers, 30% could go to a local shop alone, 65% had pocket money, 35% could cross roads alone and 13% walked to the school or work bus alone. It was only the oldest teenagers (over 17) that were travelling about independently in the community.

This means that most teenagers could not travel about the local neighbourhood without supervision. Learning to be independent in the community is another area that involves risk taking. However, the necessary skills will only be learned if a teaching programme is planned and the young person able to learn over a period of time, in small steps. For example, when crossing the road, a teenager can be encouraged to identify the right place to cross - usually a proper pedestrian crossing with lights to stop the traffic - can press the light and be in control of deciding when to cross, while still being accompanied by an adult or another teenager. Similarly, bus skills can be learned by allowing the teenager to take the lead in asking for the fare and handing over the money, with an adult in the background to help if necessary. Slowly, the support can be faded in small steps.

For some teenagers, the use of a mobile 'phone will aid their safety and independence - and reassure parents that they are safe. Important numbers can be stored so that they can be dialled with one key press if the teenager needs assistance.

The level of independence attained during the teenage years will vary considerably between individuals, and most young people with Down syndrome will continue to develop their independence significantly during their young adult life.

The reader may be interested to note that there was no significant difference in the personal or social independence skills of teenagers in mainstream or special schools and there was no significant improvement for teenagers in 1999 compared to teenagers in 1987. When we wrote about the findings of the 1987 survey, we encouraged parents to raise their expectations but we have little evidence that this has happened.

Motor skills

In the 1999 survey, everyone is able to walk, to climb stairs with one foot on each step and some 90% of teenagers can jump with both feet together and hop on one foot. Everyone can throw and kick a ball and almost everyone (96%) can catch a ball. Almost all teenagers (93%) can swim without aids and ride a tricycle, with 36% able to ride a bicycle. We did not ask about the range of other sporting activities that teenagers may be skilled in but we know that some teenagers are skilled at gymnastics, horse riding, diving, skiing, baseball and football and that these activities are an important part of their lives.

See also:

We would encourage all parents and teachers to support teenagers in a wide range of physical activities for two reasons, health and opportunities for social contacts and friendships.

About half of all teenagers are considered overweight by their parents, and this tendency to weight gain, which is more significant after puberty, can be reduced by taking sufficient exercise as well as by healthy eating. Exercise will also improve gait and posture, breathing and general fitness.

In addition, taking part in sporting activities can bring teenagers into contact with peers - both other peers with disabilities and typically developing peers. We have already suggested that this is important for social and emotional development.

Speech and Language

The communication skills of most teenagers, that is their ability to get their message across, is very good. Almost all teenagers (96%) could start conversations, participate in conversations, talk about past and future events, ask questions and use the telephone. However, getting the message across can be supported by actions and gestures, facial expressions and tones of voice and the listener's knowledge of the context and topic of the message. Almost all teenagers with Down syndrome have some speech delays and difficulties, that is, their speech is not as clear, fluent and easy to understand as that of their non-disabled peers. Some 33% were reported to have difficulty being understood by those unfamiliar with them such as assistants in shops or restaurants.

In addition to the effect of speech phonology and articulation difficulties, the intelligibility of their messages will also be reduced because they are often not able to produce fully grammatically complete sentences. All the teenagers in the 1999 study were talking whereas in 1986 there were 3 teenagers in a sample of 90 with no speech at all . There were significant differences between the spoken language skills of the teenagers in mainstream education and those in special education settings. All the teenagers in the mainstream schools usually used sentences of 5 or more words but only 61% of those in the special schools. Some 40% of the teenagers in special education settings mainly used shorter 3 or 4 word utterances to communicate, some 13% mainly only one or two words and half used 'key-word' or 'telegraphic' utterances - leaving out the grammatical words and word endings and using mainly verbs, nouns and adjectives.

See also:

Most teenagers understand more spoken language than they can use in their own expressive language. This is a very frustrating situation for them and it also often leads to the understanding of teenagers being underestimated. Importantly, the receptive language of the teenagers in the special education classrooms was not more delayed - only their expressive skills were significantly behind those of the mainstreamed teenagers. This suggests that some aspects of the inclusive education situation was enabling teenagers with Down syndrome to overcome some of the typical expressive language difficulties. One factor that the authors believe to be important is the extent of inclusion in literacy activities, where the outcomes for the two school systems are also different as described in the next section.

See also:

Only 40% of all teenagers were reported to be using more than 10 signs to communicate, though 60% were reported to understand more than 10 signs. Some 77% of the parents of the teenagers who used signs found them helpful. It is likely that most teenagers can improve their speech and language skills, and practical advice on how to assess their individual needs and improve speech intelligibility, vocabulary, sentences and communication skills is covered in the Speech and language development for teenagers with Down syndrome module.

Reading and writing

All the teenagers in mainstream education were able to read and could read short sentences and simple books - simple in the sense of containing simple sentence structures - but with age-appropriate content and interest. Almost all (94%) of the teenagers in mainstream schools could read more than 50 words and simple instructions, 83% could read items in the newspaper and 78% read for pleasure. All the teenagers in this group knew the names of the letters of the alphabet, 89% knew all the letter sounds, 78% could sound out words when reading and 72% could sound out words for spelling.

The reading achievements of the teenagers in special education were significantly behind those of their mainstream peers. Some 78% could read something and of this group, 83% could read their own name and some 'social sight' words (usually words with environmental and practical values such as 'ladies', 'gents', 'bus-stop', 'exit', 'police'). Some 39% of the readers could read more than 50 words and read simple books, 22% could read items in the newspaper, 48% could read simple instructions and 35% read for pleasure. Some 50% of the special education teenagers know the names of all the letters of the alphabet, 41% know the letter sounds, 32% can 'sound out' words when reading and 23% can 'sound out' words when spelling.

When writing skills are considered, 90% of all the teenagers could trace over and copy letters and words and almost everyone (93%) could write their name. Of the teenagers in the mainstream schools, 94% could write their family names, 83% could write simple sentences and 61% could write their own address, simple messages, simple stories and a short letter. Of the teenagers in the special schools, 48% could write their family names, 30% could write simple sentences and their own address, 17% could write simple messages, 4% could write simple stories and 22% a short letter.

See also:

The reading skills of most teenagers can be developed further during their teenage years and some may begin to read at this time. The 11-16 Reading and writing module contains detailed information on how to extend the reading and writing skills of teenagers, and how to make even limited reading abilities relevant and useful.

Number, money and time

Overall, the arithmetic skills of the teenagers educated in mainstream schools tend to be significantly ahead of the teenagers in the special schools but not their money skills. All the teenagers in the mainstream schools could recite the numbers to 20 accurately and 94% could count objects to 20 and do simple addition with numbers within this range. Half of this group could recite the numbers to 50 and a third could count more than 20 objects accurately and recite numbers accurately to 100. While all the teenagers could add simple numbers, 78% could complete simple subtraction, 28% could complete simple multiplication and 17% could complete simple division.

For the teenagers in the special schools the figures indicate that 69% could recite the numbers to 20 accurately and 52% could count objects to 20 and 61% could do simple addition. Some 26% of this group could recite the numbers to 50, 17% could count more than 20 objects accurately and 13% could recite numbers accurately to 100. While more than half of the teenagers could add simple numbers, 43% could complete simple subtraction, 4% could complete simple multiplication and 4% could complete simple division.

When we consider money skills, all but one of the teenagers relied on shop assistants to take correct sums of money. The special school teenagers tend to be doing better with 48% able to count simple amounts of money and 26% able to give an approximately appropriate amount in a shop, compared with 33% and 11% of teenagers in mainstream schools who could do these tasks.

See also:

When we consider general knowledge of time, only 20% of the teenagers could tell the time completely, all the teenagers in the mainstream schools could name the days of the week, and give their own name and age, 94% could say their own address, 89% their birthday, and 61% could name the months of the year. For the teenagers in the special schools 70% could name the days of the week, all could give their own name and 87% their age, 65% could say their own address and 43% their birthday and 35% could name the months of the year.

The 11-16 Number module contains a wide range of activities to develop number, money and time skills for teenagers. It encourages parents and teachers to continue to develop a basic understanding of the number system and simple calculations, as well as providing tips for supporting functional use of time and money.

Social and interpersonal development

Leisure interests

If we consider leisure interest and activities, watching TV was the favourite and some 80% of teenagers watched TV often, 55% were interested in pop-stars, 74% were interested in pop music. Some 40% of mainstreamed teenagers and 70% of those from special schools listened to pop music often. Some 44% of mainstreamed teenagers were interested in sports, 33% interested in the cinema and 22% in fashion, with 70% of those from special schools interested in sport, 65% interested in the cinema and 43% interested in fashion. If we consider more passive activities, some 35% read often, 38% played games often, and 27% of mainstreamed teenagers and 48% of those from special schools often enjoyed drawing. Some of the group differences may be due to the fact that there are more older teenagers (over 18 years) in the special school group. This list of interests and activities includes many that are age-appropriate but the teenagers tended to be engaged in these at home on their own, especially as many had TVs and computers in their own rooms. All but one teenager could operate the TV independently and 80% could operate computer games.


Some 58% of all the teenagers spend time with friends at least once a week. When we asked about these friends, 18% of the teenagers from the mainstream schools and 64% of the teenagers from the special schools had only disabled friends. Some 47% of the teenagers from mainstream schools and 9% of those from special schools had only non-disabled friends. About a third of all the teenagers had both disabled and non-disabled friends

This figures indicate that about 50% of the teenagers educated in mainstream schools had no disabled friends and that 64% of the teenagers educated in special schools had no non-disabled friends.

The information provided on the sort of clubs attended partly explains these friendship patterns, as 55% of the mainstream teenagers and 43% of teenagers from specials schools belong to 'mainstream' clubs, and 65% of the mainstream teenagers and 56 % of teenagers from special schools belong to 'special clubs'. There was apparently the opportunity for more teenagers to have both disabled and non-disabled friends, as for example 65% of mainstream teenagers attended 'special' clubs but 18% did not make 'special' friends there.

However, the information suggests that 35% of the mainstream teenagers never had the opportunity to make friends with disabled peers in or out of school and that some 57% of the teenagers attending special schools had little opportunity to make friends with non-disabled peers in or out of school.

Information provided on going to parties and discos supports the above picture. While 69% of teenagers from mainstream education are invited to discos and parties organised for typical peers, only 16% of the teenagers from special schools receive such invitations. Some 80% of all teenagers go to discos and parties and some 40% go as often as every month, indicating that the groups of teenagers have equally active social lives but that those in mainstream education are more likely to go to inclusive or 'ordinary' social events and those teenagers from special schools are more likely to be going to 'special' events. The teenagers' social world and friendships are being strongly affected by school placements.

In the authors' view these findings have negative implications for both groups of teenagers. The teenagers being educated with their disabled peers seem to have little opportunity to socialise in inclusive or non-disabled settings and are less likely to have non-disabled friends. This is likely to put them at a disadvantage in feeling at ease with and being able to communicate with non-disabled peers when they attend inclusive further education colleges, when they are in the workplace and when they are out and about in the community.

In contrast, the teenagers educated in mainstream schools seem to be at risk of not having the opportunity to have friends with a similar level of disability for the close, special friendships and to find boyfriends and girlfriends. Some 38% of the teenagers from the special schools had boyfriends or girlfriends yet no one from the mainstream schools had a boyfriend or girlfriend at the time of the survey.

See also:

The effects of these social experiences during the early teenage years from 11 to 16 seems to have a possibly serious consequence for some of them once they leave school. We only have a small number of older teenagers (over 17 years) who have left a mainstream school, but they seem to have more restricted social lives than the older teenagers from the special school system. It seems as though it may be more difficult for them to find friends or partners, and to settle into a social network, than it is for those from special schools.

The implications of these findings are that parents need to encourage friends with and without disabilities. The implications for schools and for an effective inclusive school system which can provide academic and social advantages are discussed further in the 'Education' section of this module.

Brothers and sisters

As has been indicated in other studies, brothers and sisters play an important part in the social lives of teenagers with Down syndrome as 83% of all the teenagers frequently join in social activities with their brothers and sisters. Only about 25% of the teenagers are reported to enjoy any of their social activities, without the support of a member of their family. As a consequence of limited independent travel skills, most teenagers are relatively socially isolated for their age.


In summary, the social and leisure interests of teenagers are age-appropriate, but they are relatively socially isolated compared to typically developing peers. Teenagers with Down syndrome have friends, but cannot meet up with them easily out of school, limiting the opportunities for close friendships.

The school placement of teenagers influences their opportunities for making friends with both disabled and non-disabled peers, and this may have longer term social and emotional consequences.

Achievements at 16 years

Many teenagers with Down syndrome will be on the way to complete independence in personal care, able to choose their own clothes appropriately for the day, wash and bathe with minimum help, make a simple snack, answer the telephone and help with household tasks, but some will still need support for daily activities. Many teenagers will be quite socially confident in school and at clubs and only need minimal support to function in these settings. However, some young people will still need a high level of support with their personal care and in social situations.

Many teenagers will be progressing with reading and writing, with some teenagers able to write short stories and record their work in lessons while others still need full support to do so. Some teenagers will be calculating with numbers to 1000 or beyond but some will still be learning to count with numbers to 20. Teenagers will be progressing with their understanding of time and money at varying rates. It is possible for teenagers to benefit from access to the full school curriculum, differentiated to their needs, whatever their rate of progress, provided that there is adequate support in schools for this to be achieved.

Most teenagers will be enjoying music, dance, drama, art and sporting activities and developing their skills at varying rates. In these activities, the enthusiasm and creativity of teachers will have considerable influence on the way in which teenagers with Down syndrome progress. Participation in these activities is not dependent on good speech and language skills and individuals with Down syndrome can often show considerable talent if given the opportunity. Mime and dance activities, for example, allow teenagers to express their understanding of emotions and behaviour in a way they cannot do in daily life.

Most teenagers with Down syndrome can behave in an age-appropriate and socially acceptable manner, at home, at school and in the community, regardless of their level of ability, if they are expected to do so. This is a very important goal, as behaviour influences all aspects of teenagers' lives, and the lives of their families. During teenage years, difficult behaviour causes stress in the family and reduces teenagers' learning and social opportunities. In adult life, a person who can behave in a socially acceptable manner can participate fully in community and social activities. In the authors' experience, less cognitively able adults with good social behaviour will be working and leading more fulfilling lives than more cognitively able individuals with poor social behaviour.

Social independence

Independence in the community will vary. Teenagers with Down syndrome who have been educated in fairly large mainstream schools will have had the opportunity to learn to find their way around a large site, to use the canteen for lunch (involving choices and the use of money) and they may be walking to school with friends, crossing roads or using the bus. Teenagers in special education may be part of much smaller communities (50 to 70 pupils rather than 1000-1500 pupils), with less opportunity to achieve these levels of independence. Out of school, teenager's opportunities will vary according to the resources of the areas in which they live. Some teenagers may walk to a local shop or club if they are very close to home, by the time they are 11 years old, but most children with Down syndrome will become more independent in their communities during their teenage years. Most teenagers in the 11 to 16 age range will still be supervised when they travel outside the home, but they should be learning to walk to local shops and to cross roads safely.

Individual differences

Influences on development

  • Social learning opportunities at home, at school and in the community
  • Social support for learning through scaffolding, modelling and teaching
  • Self-esteem, curiosity and motivation to learn
  • Biology and experience interact to influence brain structure and brain function throughout life

For all teenagers, including those with Down syndrome, developmental progress at any age is influenced by their biological make-up and their opportunities to learn and develop throughout their lives. Throughout childhood, much learning is influenced by the social relationships experienced in families and by social learning and educational opportunities with other children and adults outside the family. It is also influenced by children's self-confidence and self-esteem. Brain development is a process which continues through life and brain function and structure are influenced by learning and activity.

Additional difficulties

It is also important to remember that a teenager with Down syndrome may have additional difficulties, like any other child. A small number of teenagers with Down syndrome have additional medical complications, like seizures or other illnesses, which may affect their development. Similarly, a small number of teenagers have autistic spectrum disorders, attention deficit or hyperactivity disorder. These additional difficulties affect less than 10% of children with Down syndrome but they should be recognised and treated in their own right when they do occur. These difficulties are discussed in a little more detail below (see 'Teenagers with more severe developmental delays')

Health care needs

Teenagers with Down syndrome are at greater risk for some illnesses and for hearing and visual difficulties. Any young person's developmental progress will be influenced by illness or sensory difficulties, so that it is important that all healthcare issues are understood and addressed. The Health care section of this module provides a guide to the healthcare needs of teenagers with Down syndrome, explains assessments and treatments and gives references to further reading. It is perhaps worth noting that some illnesses will present with obvious symptoms but some may not. For example, a teenager with limited language who has an ear ache or a stomach ache may not be able to explain that he or she is in pain, except by being unhappy and, maybe, irritable or difficult. Therefore it is always important to consider and rule out illness if a young person's mood changes, they stop making progress or they are difficult, before assuming they are simply being unco-operative or naughty.

Parents and teachers of typically developing teenagers have some idea about expected rates of development, which they can use to decide whether their teenagers are making appropriate progress or whether they should be worrying about their progress. For parents and teachers of young people with Down syndrome, guidelines are equally important but more difficult to find and to interpret.

In each of the detailed modules, milestone data is included if available, for example, for speech and language, counting or reading. Young people with Down syndrome vary widely in their rates of progress. Some young people make much slower progress than others and it is not possible to predict or explain these differences fully at the present time.

Typically developing children also show a wide range of rates of progress, due to both different genetic make-ups and to social and educational learning opportunities and the range for some 85-90% of children with Down syndrome is probably due to exactly the same factors. However, as has already been identified, the development of approximately 10% to 12% of individuals with Down syndrome is being affected by additional difficulties. This group of young people show the greatest developmental delays and may be significantly more disabled as adults than the majority of individuals with Down syndrome. This is illustrated in Figure 7. The most common reasons for the more severe levels of developmental delay seem to be health issues, autism and attention deficit/hyperactivity disorder.

The spectrum of abilities in individuals with Down syndrome

Figure 7. The spectrum of abilities in individuals with Down syndrome

Teenagers with more severe developmental delays

Health problems

See also:

  • An overview of less typical developmental issues in Down syndrome

In both the authors' studies of teenagers with Down syndrome in 1987 and in 1999, it was clear that one reason for more severe developmental delay was additional health difficulties such as seizures and neurological damage. However, for some teenagers with severe developmental delay, the reasons cannot be identified. The prevalence of medical and psychiatric disorders in people with Down syndrome varies from those which have a lower incidence to those which are relatively common and some of these are described in the Health care section of this module.


It was once thought that Autistic Spectrum Disorders (ASD) were not found in individuals with Down syndrome. This is now known to be incorrect, but the incidence of ASD in people with Down syndrome remains a matter of some debate. It has been estimated to affect some 3-7% of children and adults. The reason for this uncertainty is that there have been no large scale controlled studies of this issue and, more importantly, that the diagnosis of ASD is too uncertain to produce reliable data.

The diagnosis of ASD is based on obtaining the developmental history of the individual and information about their behavioural patterns. At present there are no objective findings in ASD which are of diagnostic value. ASD is a spectrum disorder which covers a very wide range and there are many behavioural features which are associated with this group of conditions. However, many of these symptoms are non-specific in that they may be found in a large number of other disorders.

Some of the main characteristics of the condition are:-

  • A lack of behaviours in which points of interest are shared with others.
  • Inappropriate social behaviour which is not understood by other people.
  • Abnormal interpersonal relationships, expressed as the inability to develop intimate, reciprocal communication with other people.
  • Language usage which is not only delayed but abnormal in kind.
  • Rigid, unimaginative style of thinking and behaviour.
  • Play patterns which are repetitive, show a lack of understanding of the symbolic meaning of toys, and inability to pretend.
  • Obsessional/repetitive behaviours and preoccupations.

A teenager displaying one of these characteristics, or even two or three, does not necessarily have autism. In fact, a number of these characteristics are very common in young people with Down syndrome, reflecting slow development of speech, language and play skills or differences in temperament. For a diagnosis of autism to be appropriate, a majority of these symptoms need to be present.

Attention Deficit Hyperactivity Disorder (ADHD)

This condition is sometimes confused with ASD, especially if the child has severe learning disabilities. The level of intrinsic activity and liveliness in children varies enormously and the vast majority of young people with Down syndrome are normal boisterous youngsters. However, a small number are so overactive that their entire pattern of behaviour is disorganised. They are characterised by their short attention span, impulsiveness, 'silly' social behaviour, clumsiness and constant movement which is little affected by environmental influences. The response of teenagers with ADHD to the commonly used medications is interesting because they become calmer and more capable when prescribed drugs which are pharmacological stimulants.

The management of this condition consists of a combination of behaviour modification and drugs. If parents and/or carers observe behaviours in a teenager with Down syndrome which are similar to those described above it is important to obtain a diagnostic assessment from a specialist paediatrician or a child psychiatrist with experience of young people with learning difficulties to find out if the child has additional problems.