Current research has shown that an imbalance in the Kynurenine pathway plays a role in the physiopathology of neurogenerative and mental disorders (with a decrease in neuroprotective metabolites and an increase in neurotoxic products). So far the research has concentrated on the enzymes IDO 1/2, KAT (1-4), KMO and ACMSD which are the key players in this pathway. Several polymorphisms affecting these enzymes have been associated with certain disorders characterized by a deregulation of the inflammation and immune response (McCauley et al 2009,Tardito et al 2013, Lee et al 2014), but the link between these enzymes and suicidal behavior is not yet clear. The investigators hypothesize that people with history of suicide attempt would have a genetic alterations of the kynurenine pathway specific for suicidal behavior.

Inclusion Criteria:

• For the "Sucide attempters" group: Any patient aged 18 or over who has made at least one suicide attempt.
• For the two control groups: Any patient aged 18 or over, suffering from depression but has never attempted to commit suicide and any healthy subject who has never had any mental disorders.

Exclusion Criteria:

• Any patient who has expressed opposition to the use of his/her data.

All patients for whom biological samples have been collected and registered in the hospital's databank for the purpose of previously registered studies : SPAD (RCB no. 2016-A01375-46), SMART-CRISIS (RCB no.: 2017-A02634-49) and SUI-PREDICT (RCB no.: 2016-A00845-46) and several studies conducted at the university hospitals of Puerta de Hierro, Ramon y Cajal et Fundacion Jiminez Diaz in Madrid, Spain, since 2004.