Seasonal variation in affective disorders. A case register study.

This paper reports the results of a study on seasonal variation in new episodes of affective disorders, conducted using the South-Verona psychiatric case register. We found evidence for a cyclical pattern in the occurrence of affective psychosis, but this was statistically significant only for the males: there was no cyclical variation in depressive neurosis. The advantages are discussed of case register data over hospital admission statistics for the study of seasonal variation. These are particularly marked in case register areas where community psychiatric care is well developed, as in South-Verona.