Age- and sex-specific cycles in United States suicides, 1973 to 1985.

Total US suicides peak on the first day of each week, in the first week of each month, and in the late spring of each year. Although these cycles are assumed to characterize all US suicides, analyses by age and sex show that the cycles occur only in a few subpopulations. Day-of-the-week effects are found almost exclusively in middle-aged suicides; day-of-the-month effects are found almost exclusively in elderly male suicides; and month-of-the-year effects asre found almost exclusively in teenaged and elderly suicides.