Autism Spectrum Disorders

This is a term used to describe a range of autism based conditions which often start in childhood but can affect adults as well. These disorders include a variety of symptoms which are common to all sufferers although these will vary to some degree.

These disorders include:

• Mild Autism
• Classic Autism
• High Functioning Autism
• Regressive Autism
• Asperger’s Syndrome
• Childhood Disintegrative Disorder
• Rett’s Syndrome
• Pervasive Developmental Disorder

Some of these may appear more familiar than others.

The type of autism you have will affect your ability to interact with people and society. If, for example, you have a mild form of autism then you may be able to hold down a job, manage your finances and other aspects of daily life without too many problems.

In fact, your symptoms may be hardly noticeable and are considered a sign of eccentricity by work colleagues, family and friends.

It appears to be the case that anyone with Asperger’s Syndrome experiences milder symptoms than those with an autistic disorder, for example, classic autism.

How common are autism spectrum disorders in the UK?

Around 1 in every 100 children has an autistic spectrum disorder. But there are situations where autism has not been diagnosed, often in the milder cases where autism symptoms are viewed as bad behaviour or being ’weird’ but for no other reason.

There have been cases where children with a mild form of autism have been labelled as ’slow learners’ or ’difficult’and have been ignored rather than undergoing treatment.

So, we have quoted a figure of around half a million people with autism but there may be many more people with an autistic spectrum disorder who have not been correctly diagnosed.

Find out more about this in our facts and figures about autism section.

Why do more boys develop autism than girls?

There is a gender imbalance in regard to autism. Boys are three, maybe fours times more likely to develop an autistic spectrum disorder which occur for a variety of reasons.

(Source: NHS Choices/Autistic Spectrum Disorder)

There is a marked difference between the sexes in respect of high functioning autism. Many more boys than girls develop this type of autism which can be as high as a ratio of 15 to 1.

But this is much less noticeable in cases where children have learning difficulties as well as autism. In these cases there is a smaller ratio of boys to girls.

It is difficult to pinpoint exactly why there is this difference between boys and girls. There are several theories which include:

• Many of the behavioural aspects of autism such as single mindedness and interests in objects rather than people are often seen as masculine.
• Girls are considered to be better at verbal and language skills than boys. They are often more advanced in regard to social interaction and communication and their speech patterns are more sophisticated compared to boys. Boys often lag behind girls although they tend to excel in areas such as spatial awareness and manual dexterity which are one of several features of autism.
• A strong interest in stamp collecting, car registration number plates or any hobby which requires the collecting of various objects is undertaken by more boys than girls. This single minded obsession is another characteristic of autism.
• Many autistic children engage in what is known as ’challenging behaviour’ which means aggression, hyperactivity and temper tantrums. This is often due to frustration or an inability to communicate. But this behaviour is expressed by more boys than girls. Girls are more likely to self-harm when stressed, frightened or unable to deal with a new situation.

Another suggestion is that boys are more prone to disease, injury or infection compared to girls which may account for the higher numbers.

Genetics may also play a part. The female chromosomes XX appear to offer greater protection against certain diseases compared to the XY male chromosomes.

The two XX chromosomes are passed down from both parents and it may be the case that one of these pair contains a gene which protects the carrier (e.g. father) from passing this onto their daughters which also reduces the risk of her developing this disorder. But further research is needed to establish or reject this hypothesis.

Unfortunately, many cases of autism in girls are undiagnosed due to several reasons: these include GP’s failing to pick up signs of autism or the fact that girls tend to have better language skills than boys.

Plus many GP’s often assume that autism is something only affects boys. But whilst fewer girls than boys develop autism; those that do are more likely to have a severe form of autism as compared to boys.

Why is there an increase in the number of autism cases?

There has been an increase in the number of diagnosed cases of autism over the past few years but that does not mean that autism is a pervasive condition. The most likely explanation is that GP’s have become better at diagnosing an autistic spectrum disorder.

In the past, the symptoms of autism, especially the milder signs, would have been mistakenly viewed as ’shyness’ or problems with learning, i.e. educationally sub-normal, but this has since changed.

Then there has been the MMR controversy. The MMR (measles, mumps and rubella) vaccine was given to children to protect them against these childhood diseases but has been linked to an increase in cases of autism.

But research findings stated that there is no evidence of a link between the two and that the vaccine is safe to use. Plus it is important that children are protected against these illnesses as they can cause serious complications.

(Source: NHS Choices/News/MMR Jab - Autism)

So, what can you deduct from this? It is probably due to improvements in diagnosing autistic spectrum disorders and ways of treating them.