Ketamine as an Augmentation Strategy for Electroconvulsive Therapy (ECT) in Depression

Inclusion Criteria: 1. Male or female subjects 18 to 70 years of age 2. Diagnostic Statistical Manual (DSM) IV diagnosis of Major Depression (296.3), unipolar without psychotic features or Bipolar I or Bipolar II Depression without psychotic features confirmed by Structured Clinical Interview for DSM-IV (SCID-IV) interview 3. Pretreatment 24-item Hamilton Rating Scale for Depression score \> 21 4. Subjects must have an initial score of at least 20 on the Montgomery-Asbergers Depression Rating Scale (MADRS) at screen 5. ECT is clinically indicated 6. Patient is competent to provide informed consent Exclusion Criteria: 1. Lifetime DSM-IV diagnosis of schizophrenia, schizoaffective disorder, psychotic depression or any other psychotic disorder as defined in the DSM-IV 2. Current (within the last year) diagnosis of anxiety disorder, obsessive- compulsive disorder, or eating disorder that precedes the onset of the current episode of depression 3. Current diagnosis of delirium, dementia, or amnestic amnesiac disorder 4. Diagnosis of Mental Retardation 5. Baseline Mini Mental State Exam (MMSE) score \< 21 or a total score falling two standard deviations below the age- and education-adjusted mean, whichever is less 6. Any active general medical condition or central nervous system (CNS) disease which can affect cognition or response to treatment 7. Current (within the past three months) diagnosis of active substance dependence, or active substance abuse within the past week 8. Lifetime history of ketamine or phencyclidine (PCP) abuse or dependence 9. ECT within three months 10. The presence of any known or suspected contraindication to methohexital or ketamine including but not limited to known allergic reactions to these agents, uncontrolled hypertension, arrhythmia, severe coronary artery disease and porphyria 11. Pregnancy 12. Status 4 or greater according to the criteria of the American Society of Anesthesiologists 13. MRI contraindications