David H. Skuse
David Skuse is Professor of Behavioural and Brain Sciences at the Institute of Child Health, University College London, and Honorary Consultant in Developmental Neuropsychiatry at Great Ormond Street Hospital for Children. He qualified in medicine at Manchester University, and subsequently trained in academic child psychiatry at the Institute of Psychiatry and Maudsley Hospital, before moving to the Institute of Child Health in 1985 where he obtained his higher research degree. His team at Great Ormond Street Hospital provides a national clinical service for children with high functioning autism spectrum disorders.
David Skuse’s approach to research is quintessentially interdisciplinary, and translational. He has fostered a range of current national and international research collaborations on the development of social cognition, ranging from basic science (e.g. genetic influences, neuropeptides, and metabolic disorders) through epidemiology to clinical applications. He has been closely involved in the development of novel methodologies for the assessment of autistic traits in ‘high functioning’ children. He devised the computerized 3di interview for ASD and related conditions, which is used by over 20 countries worldwide, many in translation. His chief current MRC/MRF funded research program concerns identifying rare genetic risk factors for psychiatric disorder in children with intellectual disability, from a national study of up to 10,000 families in the UK.
He has served on many editorial boards and formerly edited the Journal of Child Psychology and Psychiatry; he now edits the British Journal of Psychiatry – International. He has been elected a Fellow of the Royal College of Physicians, the Royal College of Psychiatrists and the Royal College of Paediatrics and Child Health.
Autism Spectrum Disorders in females: where did all the girls go?
For many years, our conceptualization of Autism Spectrum Disorders (ASD) has been based on a male stereotype. There is a consensus that the sex ratio is at least 4-to-1, males predominating. Epidemiological evidence from around the world seems to be supportive. An influential theory of autism susceptibility — that it represents an ‘extreme male brain’ — has been promulgated with great success. I will question the validity of these assumptions.
Our current ascertainment methods for autism are biased toward the identification of males. A corollary of this biased ascertainment is that so-called ‘high-functioning’ females with autism are harder to diagnose; the 4-to-1 sex ratio is not consistent across the full range of intelligence quotients (IQ). Females with autism and high IQ are rarely clinically identified. In those with the lowest intellectual functioning, the sex ratio is no more than 2-to-1. No evidence for X-linked genetic susceptibility as a cause of male predominance has been proven. No biological mechanism by which the sex ratio varies with IQ has been identified.
In this lecture, I will discuss possible explanations for the ‘variable sex ratio’. There are three significant factors. First, our standardized measures of autism are derived from historical conventions based on the stereotypical symptom profile of boys. Second, boys with autism tend to have co-occurring symptoms and conditions that prompt clinical attention (including attention deficit hyperactivity disorder and disruptive behavior). Girls with autism, on the other hand, tend to have subtle related symptoms (such as social withdrawal, depression and anxiety), so their underlying social communication problems are often overlooked. Third, there is increasing evidence that females with autism show a greater capacity to ‘mask’ their difficulties, and this leads to the development of compensatory behaviors in those who are intellectually able. I will present empirical evidence to support these hypotheses and describe the female phenotype.