ABSTRACT
Just as schizophrenia is the most devastating psychiatric condition to affect adults, and Alzheimer's disease the elderly, autism, sometimes described as a dementia of childhood, is the most destructive disorder of youth. Indeed autism bears a number of similarities to schizophrenia, including early, erroneous ideas about an aetiology from poor parenting. In this chapter we see the autistic spectrum within the general context of other neuropsychiatric disorders characterised by speci®c delays, or rather halts, in development, and how a range of medical conditions may be associated with autism. This disorder, heterogeneous in possible causes and manifestations, is highly comorbid with the other conditions that involve the frontostriatal system to varying extents, and with which this book is concerned. We shall note its peculiar social and communicational de®cits, and its tendency to a stereotyped range of interests and behaviours, along sometimes with peculiar islands of high ability. We shall also note explanatory accounts such as a failure of central coherence, or of possession of a theory of mind, which, however, may be unable of themselves to explain all aspects of the disorder. As with schizophrenia, we shall see that any neuropathology is subtle and heritability is high, and that what is inherited may be a predisposition or susceptibility that also requires the action of certain other environmental events, perhaps at key points in neurodevelopment. Again,
as with the other disorders, we shall observe that a range of modulatory neurotransmitters, known to be active in the frontostriatal system, may be involved, particularly serotonin, dopamine and the peptides oxytocin and vasopressin. Finally, we shall review Asperger's disorder, which is closely related to autism, and Williams syndrome, which has some surprising similarities and differences.
