For people with both major depressive disorder and opioid use disorder, a randomized clinical trial compared the effects of adding either ketamine or buprenorphine to standard treatments. Ketamine produced a rapid and substantial reduction in anxiety symptoms within hours, along with a pronounced decline in opioid craving. Buprenorphine led to a more gradual but sustained improvement in anxiety over several days, with a modest initial reduction in craving that persisted afterward. Both drugs reduced anxiety and craving, but through different time courses.
Psilocybin may reduce depressive symptoms in cancer patients, with mixed effects on anxiety and time-dependent improvements in spiritual well-being and, in single-arm data, quality of life. However, due to the small number of studies, high heterogeneity, challenges with blinding and expectancy, and frequent co-intervention with psychotherapy, these findings are preliminary. Larger, rigorously blinded trials are needed to determine clinical effectiveness and safety.