Seasonal Associations Between Weather Conditions and Suicide – Evidence Against a Classic Hypothesis

The authors modeled monthly data on suicide & climatic conditions in Switzerland. Cross-correlations between the filtered residual series were calculated for the period 1881-2000, for consecutive 30-year periods, for different suicide methods, & with regard to the seasonality hypothesis, for series relying on moving 1- & 3-month frames. Positive cross-correlations emerged between suicide & temperature data for the whole time series & as well as in all consecutive 30-year periods. However, cross-correlations of data series based on moving frames showed a minor peak in associations for summer frames & a major peak in associations for winter frames. The results were not compatible with the hypothsized role of temperature in suicide seasonality. (51 refs.)