The goals of the Stony Brook High-Risk Project are to identify precursor patterns, environmental stressors, and protective factors that are differentially predictive of psychopathology. In phase I we assessed 219 families and 544 children aged 7-15, including 31 families and 80 children with a schizophrenic parent, 70 families and 154 children with a unipolar depressed parent, 58 families and 134 children with a bipolar parent, and 60 normal control families with 176 children. A 3-year followup was conducted on 84 percent of the sample, and an additional followup is underway. Our data include measures of: (1) psychological functioning of the parents; (2) the environment, including family functioning, marital adjustment, and parenting practices; (3) child adjustment, including peer, or teacher, parent, and self-ratings; (4) early signs or precursors to the development of schizophrenia or affective disorder, including cognitive slippage, attentional deficits, hedonic capacity, depressogenic attributional styles, and subsyndromal affective patterns. Considerable deviance in family functioning, expressed in conflict, marital discord, and parenting skills, was characteristic of the families with an ill parent, and this discord was related to child adjustment. Children with a schizophrenic parent showed multiple and extensive cognitive, attentional, and social impairments, and at the 18+ followup, 22.8 percent of them compared with 9.6 percent of the normal controls were assigned a DSM-III diagnosis.