Cyclothymia in the Adolescent Offspring of Parents With Bipolar Affective Disorder

The present study explored the prevalence and types of psychopathology exhibited by the adolescent and young-adult offspring (ages 15-21) of patients with bipolar affective disorder. The major hypothesis of the study was that the offspring of bipolar patients would be characterized by an increased rate of cyclothymia. Subjects included 37 offspring of patients with bipolar affective disorder and 22 offspring of patients with nonaffective psychiatric disorders. Offspring received structured diagnostic interviews, conducted by interviewers unaware of parental diagnosis. Anonymous diagnoses were derived based on Research Diagnostic Criteria. The offspring of bipolar parents exhibited significantly higher rates of affective disorder, in general, and cyclothymia, in particular, than did the offspring of nonaffective psychiatric controls. The offspring groups did not differ on rates of nonaffective disorders. These results provide further support for a continuum model of bipolar disorder, in which cyclothymia is viewed as a mild form of full syndromal bipolar illness.