Sir: As a child and adolescent psychiatrist I would like to support the observations of Gralton & Crocombe (Psychiatric Bulletin, November 1999, 23, 692). Autistic spectrum disorders are becoming much more common and this is not just a reflection of more awareness. There has been a definite increase since 1979 in the diagnosis of children with this disorder and a very small minority of people with Asperger's syndrome do show very violent behaviour which is dangerous to others with no sense of remorse and no understanding that violence is wrong.

At present it is mainly child and adolescent psychiatrists who notice this increase, but many of these young people are now reaching adult age and will need to move on to adult services.

From our experience of working with children and young people I would very definitely feel that the service provision for individuals suffering from autistic spectrum disorders and psychopathic disorders should be quite different from provision for antisocial or dissocial personality disorders.