The spring peak in suicides: a cross-national analysis.

This study evaluates the relative influence of social vs bioclimatic factors on cross-national variation in the magnitude of spring suicide peaks. Time series and cross-sectional data for 28 countries are analyzed using bivariate plots and simple correlation. Suicide seasonality (both overall and specifically as manifest by the presence of a sizeable spring peak) is positively correlated with seasonality in other kinds of social activity (measured in this study by the proportion of national work forces engaged in agriculture). However, only populations in the temperature zone exhibit suicide seasonality, suggesting some contextual influence from geographical latitude.