Low Amplitude Pulse Seizure Therapy Versus Standard Ultra-Brief Right Unilateral Electroconvulsive Therapy

Inclusion Criteria: 1. Patients in whom ECT is clinically indicated: The referrals to ECT by the primary psychiatrist (before a consult by the ECT consultant) will serve to both increase the feasibility of the study and address any ethical concerns that the patient would not undergo ECT without having a valid full indication for the procedure as well as increase the external validity and generalizability of the study. 2. Male or female patients 18 to 90 years of age 3. Current DSM-5 criteria for MDE with any SI of major depressive, bipolar, or schizoaffective disorders 4. Montgomery-Asberg depression rating scale (MADRS) with 2 or more on SI item 5. Use of effective method of birth control for women of child-bearing capacity 6. Patient is medically stable 7. No anticipated need to alter psychotropic medications for the duration of the study (except for urgent/emergent situations) 8. Ability of patient to fully participate in the informed consent process Exclusion Criteria: 1. Unstable or serious medical condition that substantially increases risks of ECT or cognitive impairment 2. Female patients who are pregnant or plan to be pregnant during the study or are breast-feeding 3. History of neurological disorder if deemed by the treating ECT physician or PI to pose a significant risk with ECT, or if there is any metal in the head or history of known structural brain lesion or skull defect that is deemed to affect cognition or safe ECT treatment 4. Implanted devices that make ECT unsafe 5. Clinical presentation of delirium or dementia 6. Active substance use disorders within 1 week of randomization 7. ECT in the past 1 month or prior failure to respond to an adequate course of ECT as deemed by the ECT physician treating the patient or the PI