Treatment-resistant depression
Treatment-resistant depression (TRD) is often defined as major depressive disorder in which an affected person does not respond adequately to at least two different antidepressant medications at an adequate dose and for an adequate duration. Electroconvulsive therapy, ketamine and esketamine, rTMS, and certain adjunctive agents are effective.
Source: Wikipedia — Treatment-resistant depression (CC BY-SA 4.0)