SEASONALITY IN VIOLENT SUICIDE BUT NOT IN NONVIOLENT SUICIDE OR HOMICIDE

Objective: Previous studies have reported seasonal or monthly variatio n in suicide. The present study was conducted in order to determine se asonality and other significant rhythms in violent and nonviolent suic ide, alone and together, and homicide. Method: Data on suicide, violen t suicide, nonviolent suicide, and homicide (categorized according to ICD-9) for all of Belgium for the period 1979-1987 were analyzed by me ans of spectral analyses. Results: There was a significant seasonality for suicide but not homicide. Seasonality was present in violent but not in nonviolent suicide. The number of violent suicides increased wi th age and was more prominent in men. The violent suicide chronograms of younger and elderly persons were quite distinct in the occurrence o f peaks in March-April and August, respectively, and lows in December- January. There was no significant relationship between violent suicide and homicide. Conclusion: Seasonality in suicide is determined by sig nificant circannual rhythms in violent suicides, which differ between younger and elderly persons.