The definition and epidemiology of clusters of suicidal behavior: A systematic review.

Suicide clusters are a rare and underresearched phenomenon which attract wide media attention and result in heightened concern in the communities where they occur. We conducted a systematic literature review covering the definition and epidemiology of the timeÐspace clustering of suicidal behavior. Most clusters involved young people. The proportion of all episodes that occurred in clusters varied considerably between studies and partly depended on study methodology (e.g., a larger proportion was found in studies of specific clusters compared with general population studies).