Suicidal disorders: a nosological entity per se?

An extensive body of data has repeatedly shown in the past decades that suicidal behaviors are associated with several external validators such as low serotonergic activity in body fluids and in brains of suicide victims, genetic transmission of suicide risk independently of transmission of associated major psychiatric disorders, and more recently association with several serotonin-related genes. Despite these concordant findings, suicidal behaviors are still not considered as a nosological entity per se in standardized classification. The aim of this study is to review the existing literature establishing the validity of this entity through clinical, genetic, biochemical, and therapeutic arguments all leading to the need to recognizing suicidal behavior as an independent and possibly dimensional clinical entity.