Seasonal affective disorder in the southern hemisphere.

To determine whether seasonal affective disorder exists in the southern hemisphere and whether there is any seasonal specificity in phenomenology, the authors compared 23 subjects who reported a winter/autumn affective disorder, consistent with earlier definitions of the syndrome, with 22 subjects who reported a spring/summer affective disorder. The subjects with winter/autumn onset were characterized by increased appetite, carbohydrate craving, and increased sleep; those with spring/summer onset reported decreased sleep and decreased appetite. Hypotheses concerning the etiology of seasonal affective disorder are discussed.