Evolutionary and genetic origin of suicide

Introduction: Every year, around one million people die by suicide throughout the world. So, understanding the biological origins of suicide can provide etiological and preventive advantages to our understanding of this complicated phenomenon. Materials and Methods: The current study is a review study aimed at assessing the validity of evolutionary hypotheses based on the newest findings of this domain. For this reason, relevant articles from the reliable scientific database until August 2018 were selected. Results: According to the literature, various models such as altruistic suicide, eusociality, the bargaining hypothesis, the parasite manipulation hypothesis etc., to some extent, can explain suicide behavior. However, no precise evolutionary mechanism yet identified. In addition, almost all of the new suicide models, particularly the crying for help model and interpersonal psychological model of suicide, are formed based on these evolutionary hypotheses. These models, along with other genetical studies, showed that suicide is not just a socio-cultural phenomenon; genes have an important role in suicide incidence. Conclusion: In sum, the evidences suggest that suicide is probably the by-product of pain rather than the direct product of natural selection.