Short-Term Temporal Cycles in the Frequency of Suicide, United States, 1972-1978

Vital statistics data for the U.S. for the years 1972-1978 have been analyzed for variation in frequency of suicide by month, day of the week, day of the month and phase of the lunar cycle. Frequency of suicide showed a peak in the spring months, a lesser peak in the fall and was lowest in December. Suicide was most frequent on Mondays.