Efficacy of Convulsive Therapies During Continuation

Prior treatment

• have a concomitant major unstable medical illness;
• have an intracranial implant (e.g., aneurysm clips, shunts, stimulators, cochlear implants, or electrodes) or any other metal object within or near the head, excluding the mouth, that cannot be safely removed;
• require a benzodiazepine with dose greater than lorazepam 2 mg/day or equivalent or any anticonvulsant due to the potential of these medications to limit the efficacy of both MST and ECT;

Other illness

• have probable dementia based on study investigator assessment;
• have any significant neurological disorder or condition likely to be associated with increased intracranial pressure or a space occupying brain lesion, e.g., cerebral aneurysm;
• have a non-correctable clinically significant sensory impairment (i.e., cannot hear or see well enough to complete the neuropsychological tests)

Lab values

• present with a medical condition, a medication, or a laboratory abnormality that could cause a major depressive episode or significant cognitive impairment in the opinion of the investigator (e.g., hypothyroidism with low TSH, rheumatoid arthritis requiring high dose prednisone, or Cushing's disease);

Other

• are pregnant or intend to get pregnant during the study;
• are unable to communicate in English fluently enough to complete the neuropsychological tests;

• are inpatients or outpatients;
• are voluntary and competent to consent to treatment and research procedures according to ECT/MST attending psychiatrist;
• have met diagnostic criteria as assessed by MINI V6.0 in CREST-MST or CORRECT-BD
• are 18 years of age or older
• achieve remission defined as HRSD-24 \< 10 and a \> 60% decrease in scores from baseline on two consecutive ratings OR achieve response on HRSD-24 defined as a 50% reduction in symptoms from baseline;
• are considered to be appropriate to receive convulsive therapy as assessed by an ECT attending psychiatrist and a consultant anaesthesiologist
• are agreeable to keeping their current antidepressant treatment constant during the intervention;
• are likely able to adhere to the intervention schedule;
• meet the MST safety criteria;
• If a woman of child-bearing potential: is willing to provide a negative pregnancy test and agrees not to become pregnant during trial participation.

Criteria the registry did not label

• Participants in the Acute Phase (bitemporal ECT) will have already met the diagnostic criteria and severity eligibility criteria specified in the protocols of CREST-MST and CORRECT-BD.
• At the time of recruitment, participants in the Continuation Phase (MST, RUL-UB ECT, Bitemporal ECT) will meet the following eligibility criteria: