Burst Suppression Anesthesia for Treatment of Severe Depression

Inclusion Criteria: * • Diagnosis of Major Depressive Disorder (MDD) or bipolar Disorder (I or II, most recent episode must be depression * Failed at least 2 anti-depressant treatments and no ECT in past 6 months * Age between 18-55 years * BMI \< 35 * Hamilton Rating Scale for Depression (HSRD) score \> 18 * Quick Inventory of Depression Scale (QIDS) score \> 10. Exclusion Criteria: * • Diagnosis of primary psychotic disorder, dysthymia, or personality disorder * Significant pre-morbid cognitive impairment * Hypertension and current use of ACE inhibitor or AR blocker medications * Symptomatic coronary artery disease or congestive heart failure * History of transient ischemic or neurologic signs during the past year * History of or susceptibility to malignant hyperthermia * Contraindication to isoflurane or propofol anesthesia (as determined by anesthesiologist) * Diabetes requiring insulin * Poor kidney function * Chronic use of benzodiazepines or opioids * Individuals incompetent to provide consent (e.g. catatonic, psychotic).