Seasonal changes in suicide in the United States, 1971 to 2000.

The seasonality of suicides in the USA increased from the 1970s to the 1990s. A significant proportion of suicide variation due to the seasonal component has been reported. Noted increments in seasonal rhythms in the latter part of the 1980s and 1990s seem to support those of Warren, et al. but contradict the conclusions of diminishing drawn by Hakko, et al., Rhimer, et al., and Yip, et al.