Gender differences in seasonal affective disorder

The purpose of this study was to ascertain whether men and women with seasonal affective disorder (SAD) differ in their clinical presentation or in their response to bright light therapy. Data from all patients who participated in our SAD clinic between 1981 and 1991 were analyzed retrospectively. A linear discriminant function analysis was performed using self-report data from the Seasonal Pattern Assessment Questionnaire and the Seasonal Screening Questionnaire (N =167 women and 43 men). SIGH-SAD ratings (consisting of the Hamilton Depression Rating Scale and an addendum for atypical symptoms) were analyzed to determine if men and women differed in clinician-rated symptoms at baseline (N = 86 women and 28 men), or in their response to phototherapy (N =43 women and 16 men). Male and female SAD patients did not differ in clinician-rated symptoms or in their response to phototherapy. However, on self-report scales, men reported more severe illness, while women reported more carbohydrate craving, a greater percentage increase in weight, and more hours of sleep per night in the winter. The linear discriminant function analysis correctly classified 93.4% of the women but only 27.9% of the men. Since we found significant differences only on self-report scales, our results may reflect a gender difference in symptom reporting. Alternatively, our findings may reflect gender differences in depressive symptomatology or differences between normal men and women in the sleep-wake cycle or in carbohydrate craving. Men with SAD may have a more heterogeneous presentation than women with SAD. There is, however, no gender difference in response to phototherapy. Depression 3:13–19 (1995). © 1995 Wiley-Liss, Inc