Characteristics of winter depression in the Oslo area (60 degrees N).

This is the first comprehensive description of winter depression (WD), as part of seasonal affective disorder (SAD), from Norway, and one of the very few from so far north. A total of 128 media-recruited people had first been screened with the Seasonal Pattern Assessment Questionnaire and were thereafter personally interviewed. The criteria for DSM-III-R mood disorder, seasonal pattern, were satisfied by 85%, whereas 73% satisfied the criteria of Rosenthal et al. for SAD. Seven percent were diagnosed as subsyndromal SAD. The main characteristics of our patient group were in reasonable accordance with other clinical SAD materials: there were 81% women; the mean age was 44 years (range: 20 to 76); the mean age for SAD debut was 24 years (range: 4 to 71); and the duration of WD was most often from October to March or April. Only 12% had ever been manic or hypomanic in summer. During their WD, most patients suffered at least one of the symptoms hypersomnia, hyperphagia or carbohydrate craving; 16% also had a craving for fatty food in winter, but this may be considered "normal" at this northerly latitude.