Seasonality pattern of suicide in Iran: A systematic review

Investigation of seasonal suicide might help in learning about the etiology of suicide committers’ behavior. Literature search indicates that a large number of preliminary studies have been carried out on this subject, in many of which seasonal and climatological aspects of suicide have been investigated. In the present study, the seasonal and time pattern of suicide incidence in Iran was determined based a systematic review. Search was performed in the national databases, namely, SID, Iranmedex, Magiran and Medlib, as well as international databases such as PubMed, Scopus and Google scholar, using such keywords as Iran/Iranian, seasonality and suicide. The technical quality of papers was assessed using checklists. Data of each of the preliminary studies were extracted in terms of general variables and such specific variables as season, month, hour, weekdays and climatic conditions. Of a total number of 49,522 documents obtained from a primary electronic search, eventually 32 papers were included in this study. The highest numbers of suicides committed were 7 and 8 in summer and spring, respectively. Similarly, among the primary studies that had reported only the monthly occurrence of suicide, the highest rate in 7 cases was spring and 7 in summer. In most of the studies (8 cases) the highest number of suicides had taken place between 1:00 and 6:00 PM. These findings indicate that suicide occurrence in Iran has a seasonal pattern, most cases committed being in spring and summer.