Atypical depressive symptoms possibly predict responsiveness to phototherapy in seasonal affective disorder.

Phototherapy was administered to 24 depressed patients with seasonal affective disorder (SAD), of which 62%, 24%, and 14%, respectively, showed improvements of greater than or equal to 50%, 25-50%, and less than 25% based on the Hamilton rating scale for depression for SAD (HAMSAD). No patients showed aggravation or side effects. Although the improvement rate in HAMSAD correlated significantly with the pretreatment severity of atypical symptoms of depression, it did not correlate with that of typical symptoms. This suggests that phototherapy is a useful treatment in SAD and that responsiveness to phototherapy in SAD can possibly be predicted by the atypical depressive symptoms before treatment.