Further observations on seasonal variation. 2. Depression

In an earlier study consultations for depression in general practice were shown to peak in the late spring and autumn, the pattern being similar to that found in hospital admission data and suicide statistics. There were differences, however, and these gave grounds for speculation about differences between the milder depressions typical of general practice and more severe depressions. To test the reliability of the findings, national prescribing figures over three years and general practice morbidity recordings over five years held by the Office of Population Censuses and Surveys were analysed. In these larger data sets the differences were no longer apparent, but there was evidence of a precipitating factor which varied in timing and magnitude from year to year, particularly in the autumn. This might account for inconsistencies in the seasonal variation noted in studies of hospital and suicide data.