The temperamental borders of affective disorders

Depending on the population studied, anywhere from half to two-thirds of DSM-III borderline disorders seem to represent subaffective expressions, principally on the border of bipolar disorder. "Borderland" may actually be a better characterization of this large temperamentally unstable terrain with a population prevalence of 4-6% (as compared with 1% for classical bipolar disorder). The temperaments include the dysthymic, irritable, and cyclothymic types which, respectively, coexist with "double depressive", mixed bipolar, and bipolar II disorders; others conform to an anxious-sensitive temperament in continuum with hysteroid dysphoric and atypical depressive disorders. Borderline "stable instability" in these patients appears secondary to affective temperamental dysregulation, which has exacerbated into a protracted emotional storm during a difficult maturational phase in the biography of a given patient.