Children with autistic spectrum disorder and a family history of affective disorder.

This paper compiles the clinical behavioral phenomenology of individuals with autistic spectrum disorder (ASD) with a family history of bipolar affective disorder (BPAD) or major depression and no identified neurological disorder, based on repeated clinical interviews during extended follow-up (ranging from six months to 21 (mean 3.9) years. Their pattern of affective and cognitive symptoms showed notable similarities across the entire group, despite wide variations in severity; was congruent with standard definitions of ASD; showed many features of childhood BPAD, including affective extremes, cyclicity, obsessive traits, special abilities, and regression after initial normal development; and differed from that of autistic children with neurological etiologies. These observations support the concept that ASD in some cases may be etiologically related to BPAD.