Study of Degenerescence CSF Hallmarks in Older Bipolar Patients

Inclusion Criteria: * male or female between 60 and 80 * french-speaking, reading and writing patient * affiliation to the French Social Security * written informed consent obtained from the patient * agree to undergo a lumbar puncture * easy accessibility for the lumbar puncture * Mini Mental State Examination (MMSE) \> 20 * bipolar patients : * type I or II * state of euthymia for at least 4 weeks * stable psychotropic drug treatment for at least 8 weeks * no electroconvulsive therapy during the 6 months before inclusion * distribution in the "with cognitive disorder" or "without cognitive disorder" group is function of the result of the neuropsychological evaluation Non-inclusion Criteria : * severe visual or auditory disorder * advanced lumbar osteoarthritis * history of severe head injury, neurological disorders, diagnosed dementia * addiction weaned for less than 12 months * forced hospitalization in psychiatry * MRI contraindications * LP contraindications Exclusion Criteria: \- at least one of the outcome measures can't be performed : * MRI * LP : anticoagulation, bad accessibility