The phenomenology of depressive illness in people with a learning disability and autism.

People with autism may develop new behaviours in adolescence or early adult life, in addition to those associated with the primary disorder. Some of these behaviours have been postulated to be symptoms of depressive disorder. This article notes the methodological problems of investigating depression in people with autism. The authors also attempt to clarify the symptoms that may be significant in diagnosing depression in this group, by using treatment response methods.