Title: Seasonal effects on suicide rates - Wikipedia
Headings: Seasonal effects on suicide rates
Seasonal effects on suicide rates
Contents
General effects
Popular belief
Related factors
Gender
Biochemistry
Environment
Psychology
See also
References

Content: Bridges's study focused on seasonal effects on suicide risk by examining the monthly distribution of suicides in the 1970s, 1980s, and 1990s via a "harmonic time series model" with six observable harmonic cycles within each consecutive year. The results show a consistent pattern of suicide risk with most suicides occurring in the spring/summer and the fewest during the winter months. Specifically, Bridges found that in the 1970s "about 47% of the total variances can be explained by the seasonal components" within that given decade (with more suicides in spring/summer). In the 1980s, "the seasonal component of suicide incidence for the time period 1981 through 1990 is clearly significant and records about a 27.7% increase in seasonal contribution by comparison with the previous period". In the 1990s, "the significant seasonal rhythm were explained in 63% of the total variation". According to Bridges, recent research from industrialized countries (including Finland, Sweden, Australia, New Zealand, England, and Wales) has provided enough information to show a decrease in seasonal effects on suicide rates over the past few decades. In the case of Greece, seasonal variations in mortality from suicide are "more frequent during the spring and summer months…but [have] no regular annual rhythm". The Greek researchers proposed that "the seasonal variation of suicide follows more closely to the seasonal variation of sunshine, rather than the corresponding variation of temperature". Few scientific assessments have focused on seasonal suicide Epidemiology of suicide variations in the southern hemisphere. Studies in Brazil have shown that "the peak number of suicides occurred in spring (November) in men and women of Rio Grande do Sul state and in men of Paraná and Santa Catarina states, and in early summer (January) for women of Paraná state."