Adolescent suicide clusters: evidence, mechanisms and prevention.

Cluster suicides account for an estimated 5% of all teenage suicides in the USA. Not all hypothesised clusters are verified, however, when submitted to statistical analysis. This paper reviews possible mechanisms underlying adolescent cluster suicides using the "infectious disease model", key concepts of which are host susceptibility, modes of transmission, degree of virulence, and dose dependency. Preventive measures against cluster suicides are reviewed, including primary prevention against youth suicide, tempered media reporting of suicide, and "postvention strategies" directed to communities affected by suicide.