Deep Brain Stimulation for Severe Anorexia Nervosa

Inclusion Criteria: 1. Diagnosis of Anorexia nervosa according to DSM V criteria. 2. Age 18 to 65 years. 3. Chronic, treatment-resistant anorexia nervosa, defined as: * Anorexia nervosa evolving for at least 7 years. * Inability to maintain a BMI ≥ 17kg/m² for 2 months following hospitalization in a center specialized for the management of patients suffering from eating disorders according to the criteria of the French Federation of Anorexia and Bulimia nervosa and the Directorate General of Care Provision (Direction Générale de l'Offre de Soins - DGOS, in French). Failure of at least 2 hospitalizations in a specialized center during the history of the disease. * Inability to maintain a BMI ≥ 17kg/m² for more than 3 consecutive months during an outpatient treatment conducted by a team specialized for the care of patients suffering from eating disorders according to the criteria of the French Federation of Anorexia and Bulimia and the Directorate General of Care Provision (Direction Générale de l'Offre de Soins - DGOS, in French) in the year preceding the inclusion. Failure of at least 2 outpatient treatments conducted by a specialized team during the AN care. 4. Impaired psychological, social and occupational functioning defined by a score ≤ 45 on the Global Assessment of Functioning Scale. 5. Anorexia nervosa is judged to be the primary disorder if there are psychiatric comorbidities such as depression, anxiety disorder, obsessive-compulsive disorder, or personality disorder by at least two independent experts. 6. The patient is able to comply with the operational and administrative requirements of the study and is able to complete the protocol forms. 7. Patient provides written informed consent. 8. Patient is drug-free or on a medication that has been stable for at least 6 weeks at the time of study entry. 9. If female subject and of childbearing age: use of an effective method of contraception. 10. Membership in a health insurance plan or beneficiary. Exclusion Criteria: 1. Presence of an Axis I disorder that is primary to anorexia nervosa. 2. Presence of a personality disorder that could compromise compliance with post-surgical follow-up assessed by 2 independent experts 3. Presence of severe neurological pathology or significant MRI abnormalities (excluding anorexia-related atrophy). 4. Cognitive and intellectual ability to understand the risks and constraints of the technique or to give informed consent. 5. Albumin levels \<30g/L. 6. Presence of medical contraindications to undergo implantation of a DBS system or to realize an MRI (pacemaker). 7. Pregnant or breastfeeding woman. 8. Previous DBS. 9. Trusted person and/or family object to patient's participation. 10. Contraindication to general anesthesia.