Clinical Research Directory

Inclusion Criteria: * Diagnosis of major depressive episode (MDE), in accordance with the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5), in the context of unipolar major depressive disorder or bipolar affective disorder. * 18 years or older in age. * Treatment resistant depression at Stage II of the Thase and Rush classification.56 * Baseline Montgomery Åsberg Depression Rating Scale score of ≥ 20 (moderate-to-severe depression severity).57,58 * No increase or initiation of new antidepressant therapy in the four weeks prior to screening. * Demonstrated capacity to give informed consent. Exclusion Criteria: * Inability to provide informed consent. * Medically unstable patients at the discretion of the investigator. * Concomitant neurological disorder or a history of a seizure disorder. * Participants who are pregnant. * Current substance use meeting DSM-5 criteria for substance use disorder. * Per DSM-5, had ever met diagnostic criteria for schizophrenia, schizoaffective disorder, schizophreniform disorder or delusional disorder as assessed by the Mini-International Neuropsychiatric Interview (MINI) at the time of screening. * Diagnosis of any other mental disorder that is the participant's primary diagnosis or main mental health syndrome of concern at the time of screening, which may significantly affect psychiatric status and assessed as likely to impact trial participation, in the clinical judgement of the investigator.