Correlation between suicide and meteorological parameters

Objective: The aim of this study was to investigate the link between suicide and meteorological parameters in the 23 wards of Tokyo, Japan.
Materials and methods: Monthly data (from January 2008 to December 2012) of suicide stratified by the type of suicide, i.e. hanging, drowning and jumping, were obtained from the Tokyo Medical Examiner's Office official web site. Monthly meteorological parameters (atmospheric pressure, air temperature, humidity and daylight hours) in the 23 wards of Tokyo were also used for the required period. The effects of meteorological parameters on suicide were explored.
Results: The number of suicides was 110.4 ± 14.7 (80–149) for men and 55.6 ± 9.1 (41–87) for women in the 23 wards of Tokyo, Japan. The mean air temperature was 16.6 8C ± 7.7 8C (4.8–29.6 8C). The number of suicides by drowning for men was significantly and positively correlated with air temperature, and weakly and positively correlated with humidity. In addition, the number of suicides by drowning for men was significantly and negatively correlated with atmospheric pressure.
Conclusions: The number of suicides by drowning was associated with meteorological parameters, especially in men, in the 23 wards of Tokyo, Japan.