Symptom ratings of 126 offspring of 59 families were made by both parents, one of whom had previously been diagnosed as having a primary affective disorder of either bipolar or unipolar type. Unipolar offspring were found to have significantly more symptoms on factors measuring conduct problems, anxiety, and impulsivity/hyperactivity. Divorced families had higher symptom scores on the antisocial and muscle-tension factors. Female unipolar offspring were significantly more anxious than male unipolars or bipolars. Results were interpreted as reflecting a greater impact of home environment on the unipolars and a genetically determined later onset for bipolar depressive illness.