Seasonal Variation in Suicides and in Deaths by Unintentional Illicit Acute Drug Intoxications

In order to assess whether substance-abusing people show a higher risk of death from unintentional acute intoxication in specific periods of the year, & whether this unevenly distributed risk is subject to the same seasonal influences seen in suicides, the authors studied a total of 15,792 drug-related deaths & 20,332 suicides among Italians, age 15-44, from 1984-2000. A clear seasonal variation was found for suicide in both genders, recurring on a significnat circannual cycle. No circannual cycle was observed in the monthly distribution of drug-related deaths, which seem to be influenced by non-casual oscillations following a thrice-yearly cycle, linked to a significantly more evident 6-month recurrence. (38 refs.) JA