» Behaviour

Autistic Spectrum Disorder

What is the nature of autistic spectrum disorder in CdLS?

Several recent studies of individuals with CdLS have indicated that autistic-like characteristics are associated with CdLS. The three core characteristics of autistic spectrum disorder are:

1. Poor or unusual social interaction skills

2. Delayed development or difficulties in both verbal and non-verbal (e.g. gestures, pointing and showing) communication.

3. The presence of repetitive behaviours, an insistence on sameness, restricted interests and behaviours such as lining objects up.

In trying to understand autistic spectrum disorder in CdLS it is important to compare children and adults with the syndrome with other children with the same degree of intellectual disability.

This means we can be sure that any differences are associated with the syndrome rather than just being caused by an intellectual disability.

When we do this our research shows that people with CdLS are more likely to reach the diagnostic cut-off scores for autism on an observational assessment of autistic characteristics than people with Cri du Chat syndrome (CdCS) (who have a comparable level of ability and receptive language skills).

A diagnostic cut-off score is the minimum score which an individual with a confirmed diagnosis of autism would achieve.

Figure 1 shows the percentage of individuals with CdLS and CdCS who score above the diagnostic cut-off for autism on the communication scale, the social interaction scale and total score of the Autism Diagnostic Observation Schedule.

The figure shows that approximately 60% of people with CdLS score on this assessment at a level that would be expected to be observed in individuals with autism.

This does not necessarily mean that all individuals with CdLS should receive a diagnosis of autism.

Rather it suggests that autistic-like characteristics are common in individuals with CdLS and that some people with CdLS might be considered to fall within the autistic spectrum.




Figure 1: The percentage of individuals with CdLS and CdCS who score above the diagnostic cut-off for autism on the communication scale, the social interaction scale and total score of the Autism Diagnostic Observation Schedule.

The graph shows that more individuals with CdLS than individuals with CdCS score above the diagnostic cut off for autistic spectrum disorder. The diagnostic cut off score indicates the minimum level that an individual with confirmed diagnosis of autistic spectrum disorder would achieve.

When we look at the nature of the autistic-like characteristics in people with CdLS in more detail, our findings suggest that impairments in communication are the most prominent autistic-like characteristic associated with the syndrome.

Although we have yet to identify the nature of communication impairments in CdLS more precisely, our results and observations, and those of past research, suggest that both verbal and nonverbal communication skills are compromised.

Additionally, in those individuals who develop verbal communication, reluctance to use speech in particular environments, social situations or with unfamiliar people seems to be a very common problem.

This is called selective mutism and we think the prevalence may be as high as 10% in people with CdLS who are able to speak.

In addition to impairments in communication, our results suggest that social interaction skills might also be compromised in CdLS.

However, we think that the nature of these difficulties might be somewhat different to those observed in individuals with a diagnosis of autism.

From our observations and consultations with parents, social difficulties in people with CdLS are likely to take the form of social anxiety.

This means that people with CdLS might find social situations highly anxiety provoking; this in turn might lead to social withdrawal or reluctance to take part in group activities.

Others might appear extremely shy when around unfamiliar people and take time to ‘warm up’ in unfamiliar environments.

Physical signs of anxiety include becoming pale, starting to shake, avoiding eye contact and looking tense and uncomfortable.

With regard to repetitive behaviour our recent research suggests that “compulsive-like” behaviours are very common in CdLS, particularly tidying up and lining up behaviours.

These types of repetitive behaviours are also commonly observed in children and adults with autistic spectrum disorders.

What is the cause of autistic like characteristics in CdLS?

There are several explanations for the social, communicative and behavioural difficulties experienced by people with autistic spectrum disorders.

One of these, which might help us to understand the cause of autistic-like characteristics in people with CdLS, such as difficulties with social interactions, is the ‘Theory of Mind’ account.

This suggests that people with autistic spectrum disorders do not develop the ability to understand that their own thoughts and beliefs about the world may be different to those of other people.

This means that when faced with a social situation people may find it difficult to understand or ‘read’ the socialsituation and thus social interactions become anxiety provoking (see Box 1).



Fred puts his bar of chocolate in the green box and then leaves the room.

While he is away, his Mum moves his chocolate bar to the blue box.

Where will Fred look for his chocolate bar when he comes back?

Children with autistic spectrum disorders find it very difficult to understand that Fred has different knoledge about the situation to themselves and will be more likely to answer that Fred will look in the blue box for his chocolate as this is where they know the chocolate is.

Children with good theory of mind skills understand that Fred will look in the green box, as this is the last place he saw the chocolate.

A second theory, the ‘Executive Dysfunction’ account, might be useful in explaining some of the repetitive behaviours observed in the syndrome. This theory suggests that people with autistic spectrum disorders have difficulty in regulating their behaviour.

This includes stopping an ongoing response or behaviour, generating new responses and behaviours when they are needed and not starting inappropriate responses or behaviours.

This means that people might find it difficult to move from one activity or from one behaviour to another (and so keep repeating the same behaviour or activity) and find it difficult to not start a behaviour or response when that behaviour is not appropriate (even though they “now” they should not show a behaviour; (see Box 2).



In this task, the individual is asked to read the colour of the ink the word is printed in and not the word itself. In doing so, the individual must inhibit the typical response to read the word and focus on the colour of the print. People with autistic spectrum disorders find it difficult to inhibit the typical response and might be slow to complete this task. Try to do this quickly and you will see what we mean!

What parents and carers can do to help with autistic characteristics in CdLS

The nature of autistic-like behaviours and characteristics in people with CdLS is extremely variable. Consequently, the way in which these behaviours and characteristics are managed will vary according to the level of ability of the individual and the precise nature of the difficulties.

The following section provides a brief overview of some of the types of interventions that have been demonstrated to be useful in helping individuals with autistic spectrum disorders.

Communication Skills

For those individuals who have not developed verbal communication, encouraging nonverbal communication skills (such as gesturing, pointing and showing), the use of objects of reference or formal sign or picture exchange system, such as Makaton sign language or PECS, may be important.

However, input from speech and language therapists and educational specialists are critical to make sure the method is matched to the child.

Giving the individual plenty of warning about any changes to the environment or routine might help to make the changes less anxiety provoking for the individual.

Rewarding the use of nonverbal communication skills by responding to the individual in some way (this might be responding to a request or simply engaging with the person) may help to encourage the individual to use these techniques more consistently and increase motivation to use their skills.

The aim in this situation is to ensure that formal nonverbal strategies are more effective or efficient for the individual than other less appropriate communication strategies that the individual might have developed.

For more able individuals who develop verbal communication skills, role-play techniques can be used to teach people to increase the range of conversational topics and encourage more sophisticated conversational skills.

This technique can be used to practice how an individual might introduce himself in a social situation or respond to common social questions. Encouraging initiation of conversation can be more difficult to develop.

Social Interaction skills

For younger children, or those who have not yet developed communication skills, a technique called Structured Interference has been used in individuals with autistic spectrum disorder to encourage and facilitate social interaction.

Structured Interference helps the individual to understand the value of social interaction with others.

The technique involves parents or carers engaging with the individual during what might typically be solitary play and withholding an object that might be required to complete the activity (such as a piece of a jigsaw puzzle or a block for building).

The individual would need to engage in some way with the adult in order to obtain the object and finish the activity.

This technique can be extended to encourage individuals to engage with siblings.

For older children or those who have developed verbal communication skills, teaching simple conversational skills and appropriate responses to social questions can be helpful.

Role-play techniques similar to those described above can be a useful way for the individual to ‘practice’ social interaction skills and be better equipped for social situations when they arise.

Repetitive Behaviours

For some children and families, repetitive behaviours, rituals or insistence on sameness behaviours are a source of great difficulty and disruption to family life.

As the individual gets older, repetitive and restricted interests might become increasingly marked and restrict the individual and their family from engaging in other activities.

It is important to note that repetitive behaviours may be difficult to stop completely and even if this is achieved, there is a good chance that the individual will begin to engage in a different type of repetitive behaviour in its place.

Consequently, the aim is to manage repetitive behaviours by reducing the severity or frequency of the behaviour, establishing rules regarding when and where the individual is allowed to engage in the behaviour or adapting the focus of the behaviour to something that is more appropriate.

Using these management techniques early on in younger children or when the behaviours first start to appear might make these behaviours easier to manage in the future.

A popular technique used to reduce or replace repetitive behaviours in individuals with autistic spectrum disorder is the ‘Graded Change Technique’.

This approach works to gradually change the repetitive behaviour by slowly, but progressively, changing the nature, severity or frequency of the behaviour.

For example, slowly limiting the number of objects that the individual is allowed to line up or restricting the number of rooms in the house in which the individual is allowed to engage in the behaviour, limiting the number of ‘special objects’ the individual is allowed to carry with them or establishing rules regarding when and where the individual is allowed to carry the objects with them.

Reaching Out newsletter
December 2006