Seasonal variation in suicide and homicide: a question of consistency

Summary Seasonal or monthly fluctuations in suicides and homicides were analysed using US mortality data for the years 1969–78, using periodic regression analysis. The results were generally consistent (year-to-year) over the 10-year period. The pattern for suicide was distinctly seasonal: it was above average all spring and below average all winter. For homicides, the pattern was more monthly, with July–September and December being above average times and January–June being below average.