Suicidal behaviors (SB) are a major health problem in France : 10 000 suicides and 220 000 suicide attempts every year. SB management is therefore a major public health issue.

Evidence associated dysregulation of the serotonergic system and the hypothalamic-pituitary-adrenal axis to vulnerability to SB. Recent data point to linke these abnormalities with neuroinflammatory clues, glutamatergic function and neuronal plasticity. There is a need to better understand the physiopathology and develop diagnostic and therapeutic tools in SB.

The investigators hypothesize that increased peripheral biomarkers of inflammation would correlate to a disturbance of the cerebral metabolites, such as glutamate and NAA, especially in suicidal patients.

Our aim is to compare rates of cerebral metabolites, in particular the complex glutamine/glutamate, in cerebral areas involved in suicidal vulnerability (the anterior cingulate cortex and the orbito-frontal cortex) between person with unipolar disorder with and without suicidal attempt.

69 patients : 23 with suicidal thoughts and attempt, 23 with suicidal thoughts without attempt and 23 healthy volunteers.

2 visits :

• Inclusion visit (V0) : (Day 1)

  o Clinical interview : self and hetero assessment questionnaire

• Visit V1 (as soon as possible, day 1 if available) :

  • MRI (spectroscopy)

Non-specific inclusion criteria:

• Having signed informed consent
• Able to understand nature, aims and methodology of the study

Specific inclusion criteria :

• Suicidal patient with suicide attempt :

  • Persistent depressive disorder according to the Diagnostic and Statistical Manual of Mental Disorders - V (DSM-V) criteria, and evaluated by the Mini International Neuropsychiatric Interview (MINI)
  • Hamilton Depression Scale > 7
  • Suicide attempt < 1 week

• Suicidal patient without suicide attempt :

  • Persistent depressive disorder according to the Diagnostic and Statistical Manual of Mental Disorders - V (DSM-V) criteria, and evaluated by the Mini International Neuropsychiatric Interview (MINI)
  • Hamilton Depression Scale > 7
  • No history of suicide attempt

• Healthy volunteers :

  • No psychiatric history
  • No history of suicide attempt

Exclusion criteria:

• Actual somatic, neurological or inflammatory pathology (C-Reactive Protein > 10mg/L)
• Traumatic brain injury with loss of consciousness
• Antibiotic treatment or anti-inflammatory treatment
• Actual toxic abuse according to DSM-V (except tobacco and alcohol)
• Actual or passed history of psychotic disorder
• Patient on protective measures (guardianship or trusteeship)
• Deprived of liberty subject (judicial or administrative decision)
• Pregnant women or breastfeeding
• Contraindications to MRI scan