Seventy-two proband children aged 10-17 of bipolar parents, matched with 72 control children of normal parents, were investigated using DSM-III diagnostic criteria and multiple sources of information. The psychopathology rate in children (61% in probands versus 25% in controls) was related to the impact of psychic disorders on the children's adaptive functioning. The effect of several variables describing the psychiatric status of both parents and familial environment on the severity of psychopathology in children was analysed. Disordered and non-disordered probands were compared with respect to illness characteristics of their parents, familial environment, personality traits, and IQ by means of canonical discriminant analysis.