The effect of season and weather on suicide rates in the elderly in British Columbia.

OBJECTIVES The authors examined the relationship of suicide in the elderly (65 years and older) to season and weather and compared it to that in the younger population (10-64 years). METHODS Information on suicides and on weather was obtained for British Columbia for the period 1981 to 1991. The association of suicide with season and weather was assessed using Poisson regression. RESULTS Whereas younger suicides were associated with season, showing a spring-summer peak, elderly suicides were associated with actual weather. They increased with higher mean daily temperature for the current month (RR = 1.16, 95% CI 1.05-1.28 for each 2.5 degrees C change in mean temperature), and with lower mean daily temperature for the preceding three months (RR = 1.12, 95% CI 1.01-1.23). CONCLUSIONS Elderly suicide rates appear to be affected by deviations of monthly mean temperature from values expected for that time of year. Increased support by service agencies at times of predicted high risk is suggested.