Interest in using psychedelics to treat treatment-resistant depression is growing, but evidence for classic psychedelics like psilocybin, LSD, and ayahuasca/DMT remains limited, though early results are promising. Atypical psychedelics such as ketamine have also been studied. Researchers caution that the field may be experiencing a hype bubble. Future work should identify the essential components of psychedelic therapies and their neurobiological mechanisms to support clinical adoption.
In people with treatment-resistant depression who do not have psychosis, intravenous ketamine works as well as electroconvulsive therapy (ECT) overall. Among outpatients with moderately severe or severe depression, ketamine produced greater improvement in depressive symptoms than ECT. In contrast, inpatients with very severe depression improved more with ECT early in treatment, though by the end of the three-week course both treatments were similarly effective. Higher premorbid intelligence and a diagnosis of posttraumatic stress disorder were linked to greater improvement with ECT, but not with ketamine. These findings may help patients and clinicians decide between the two treatments.