Is bipolar II a unique disorder?

The authors investigated differences between 27 outpatients who met RCD "definite" criteria for bipolar II disorder and 188 unipolar patients on several dimensions: clinical characteristics, response to acute treatment, personality profiles after recovery, and family history. The bipolar II group was found to have a higher morbid risk for depression among fathers, a greater incidence of past suicidal attempts, and a greater frequency of psychomotor retardation. A high degree of selectivity for protocol inclusion may account for the similarity seen between the bipolar II group and the unipolars on the other variables examined. The present findings suggest these two groups can be successfully combined in the treatment of recurrent depressive episodes.