From social exclusion to psychological pain.

With one million deaths worldwide, suicide is a major health problem. New hypothesis to better understand this complex phenomenon are needed because efficient therapeutic strategies are still lacking. The stress-vulnerability model is largely admitted to understand suicidal act; i.e. only predisposed subjects, under stress condition, will attempt suicide. Unbearable pain, particularly psychological pain, is a frequent theme of suicide notes. Subjects with a higher propensity for mental suffering may be at greater risk of suicidal act. In most cases, suicide attempters have reported psychosocial stress leading to a social devaluation or a feeling of exclusion. Dysfunctional social cognitions could be involved in suicidal behavior through two pathways because it produces pain and increases sensitivity to some social events. Brain imaging is a helpful tool to better understand in vivo the neuroanatomical basis of suicidal vulnerability and its link with social as well as psychological pain. Neuroimaging studies mainly showed the involvement of prefrontal and cingulate cortices in both psychological pain and suicidal vulnerability. In addition, there is increased evidence of an overlap between psychological/social pain and physical pain. By stressing that pain is core to suicidal behaviour, we may provide new avenues for improving the comprehension of physiopathology (i.e. opioid system) and treatment of suicidal behaviour (i.e. pain becoming a therapeutic target).