Asperger’s Syndrome and High Functioning Autism: Shared Deficits or Different Disorders?

Gillberg, C, M.D., Ph.D., The Journal of Developmental and Learning Disorders;5:79-94.

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The terms are more likely synonyms than labels for different disorders.

I should perhaps add that it was not Asperger who first described the syndrome that now bears his name. A Russian neurologist, Eva Ssucharewa, published a paper in the mid 1920’s in which she described “schizoid personality disorder”in children. Reading Sula Wolff’s translation of that paper it becomes clear that Ssucharewa described the core deficits and major hallmarks of autism long before Asperger or Kanner (Ssucharewa 1926, Wolff 1995).

The ICD-10 (WHO 1992) and DSM-IV (APA 1994) criteria for the syndrome are virtually identical to each other. They are problematic in that they specifically exclude cases with signs of early language, developmental or social delays. Virtually nobody with an autism spectrum disorder fits these criteria. Asperger’s own cases do not meet criteria for DSM-IV Asperger’s disorder.

In clinical practice, the DSM-IV criteria for Asperger’s disorder are not helpful. I have yet met a patient with the clinical presentation that Asperger described who was completely normal in his development early on. Another problem is that the actual symptom threshold for qualifying for a diagnosis is very low; only two social and one behavioural symptom are required to reach diagnostic status. The ICD-10 has the additional problem that there is no specification that symptoms have to be handicapping in daily life. There are no universally agreed criteria for high-functioning autism.

There is always marked social impairment in Asperger’s Syndrome, usually showing an extreme egocentricity. There is mostly a much decreased ability to interact with peers, often coupled with a lack of desire to interact with peers, a lack of appreciation of social cues, and socially and emotionally inappropriate behaviours.

Several years may pass before family, peers, relatives and teachers understand that something is seriously amiss, and it may only be with hindsight that they realise that there was never a period of normal development. The narrow interest pattern, was something that Asperger himself put a lot of emphasis on. He felt that this interest should lead to the exclusion of other activities, or be very repetitive, or be more relying on memory than underlying meaning. Even though the narrow interest pattern is highly characteristic of the most typical cases of males with Asperger’s Syndrome, there are those, and particularly those females, who otherwise fit the criteria for the disorder, who do not demonstrate this feature. Some girls (and a very few boys) with the other core features of the condition have a strong tendency to avoid demands and to always say “no”. It is as though their main interest in life is to say no, negative things, and to go around “being bored”. They themselves cannot seem to find anything to interest them.

It is common for a child with Asperger’s Syndrome to have “delayed”expressive language development; they do not speak at an early age, even though you had the feeling that they would have been able to if they wanted to/felt the need to. I certainly see a number of kids who say nothing for two-three years and then suddenly start speaking because they “have something to say”. Some of them actually say: “Why should I speak before I have something important to say?” There are also children who, are able to read before they start speaking. They have superficially expressive perfect language and they are very often formal and pedantic in their style and they have, most of them, this very odd prosody.

Incidentally, it was only towards the end of his life that he believed that the syndrome could occur in any form in females. He thought it was an exclusively male disorder. Odd and awkward gait, strange posturing (sometimes approaching catatonia) and a mask-like facial expression are all common features.

The five prevalence studies -which have all come from the Nordic-countries - are in relatively good agreement, and it would seem reasonable to conclude that the rate of the disorder is about one in 200 of the general population of school age children.

Male: Female Ratios
The boy: girl ratio in most studies of Asperger’s Syndrome have been reported to be 5-10:1. Both Asperger and Kanner described mostly prototypical boys, and that, therefore, our way of conceptualising the syndrome is based on the phenotypical expression in males, not in females. Interestingly, we have found a high rate of Asperger’s Syndrome/high functioning autism/PDD NOS in female teenagers/adults with anorexia nervosa and selective mutism.

Asperger’s Syndrome is very often comorbid with at least one other condition. According to the population-study by our own group, tics (including full-blown Tourette Syndrome) and ADHD are the most common comorbidities, each occurring in more than half of all clear-cut or suspected cases. Developmental co-ordination disorder (DCD) is almost universal, but then, at least according to some of the diagnostic algorithms, clumsiness is part and parcel of Asperger’s Syndrome, and it might therefore seem redundant to list DCD as a separate disorder.

Depression quite often develops in the pre-adolescent or adolescent period in children who have high-functioning autism or Asperger’s Syndrome. This may either be a reflection of comorbidity with manic-depressive illness or be seen as a reactive condition following in the footsteps of feeling socially awkward and of being an “outsider”. Many adults with Asperger’s Syndrome or high-functioning autism apply for psychiatric help but are only occasionally correctly diagnosed as having an autism spectrum disorder. We have seen our previous patients diagnosed with borderline personality disorder, antisocial personality disorder, paranoid disorder, psychosis, and schizophrenia. It may be a matter of the adult psychiatrist not being familiar with the history and symptoms of an individual with Asperger’s Syndrome/high functioning which makes him/her liable to make a diagnosis of a condition with some overlapping symptomatology for which there is a well-known framework. Alcoholism appears to be much over represented in Asperger’s Syndrome as compared with the general population, but the studies published to date have either been on potentially biased groups or included very small samples making it impossible to draw any generalised conclusions at this stage.

Here are just some of the things that have been associated in a few studies with Asperger’s Syndrome. The study was just completed on Megalencephalus, that is large head size in Asperger’s and Autism suggest that it’s only in the very high functioning group that you’ll find a large excess of individuals with big heads. In fact 24% of classic Asperger’s cases we have consistently macrocephalus.

I have met many individuals with Asperger’s Syndrome who have superficially excellent outcomes, who have had a university degree, an excellent job, and a family. Nevertheless, the spouses of the young Asperger’s Syndrome men that we followed up still feel that their husbands have some terrible problems. The men themselves feel that they are fine and they’re doing really well and there is not a major problem. Some of them have children. Unfortunately, at least in one case, that the child has turned out to have severe autism.

So, in conclusion, there is no good evidence, I think, that so-called high functioning autism and Asperger’s are different disorders. When we use these concepts, we are probably referring to the same group of individuals, and depending on where we work, and what history we have, we tend to use one diagnosis more than the other.