This study reports findings of the Edinburgh High Risk Study four years after it began. This study is designed to explore the pathogenesis of schizophrenia by examining a large sample of young adults aged 16-25 years who are at enhanced risk of developing schizophrenia by having two close relatives with the disorder, and comparing them with matched controls. This paper presents comparisons of the high risk subjects, well controls and subjects with first-episode schizophrenia in terms of demographic, childhood, psychopathological, educational and employment, forensic and social work variables. High risk subjects have more psychological difficulties, poorer educational and employment attainment, and more social work contact than controls. The enhanced social work involvement related to the presence of a schizophrenic parent (especially a mother) but the other difficulties could not be attributed to that situation. Neurotic, partially held psychotic and fully held psychotic symptoms all occurred in both subjects and controls, but all were significantly more common in high risk subjects. Clinical schizophrenia has so far developed in 10 high risk subjects and in no controls. Possible confounding effects of drug or alcohol misuse were considered but were found unlikely to be important.