Ketamine and its enantiomers show rapid-acting and sustained antidepressant effects in treatment-resistant patients with major depressive disorder and bipolar disorder. Clinical studies demonstrate that (R,S)-ketamine has rapid and sustained antidepressant activity in these populations. Preclinical data suggest that (R)-ketamine may exert longer-lasting antidepressant effects than (S)-ketamine in animal models, with potentially fewer side effects. (S)-norketamine also exhibits rapid and sustained antidepressant effects similar to (S)-ketamine but without causing behavioral and biochemical abnormalities, making it a potentially safer alternative.
Existing treatments for substance use disorders (SUD) are only partially effective. Psilocybin, a hallucinogen with a chemical structure similar to serotonin, may offer a new treatment option. Psilocybin administration spikes cortisol levels and activates the executive control network, increasing control over emotional processes and relieving negative thinking and persistent negative emotions. Preliminary data from ongoing human studies on alcohol and smoking addiction show promising effects on substance use. Psilocybin has low risk of toxicity and dependence and can be used safely under controlled conditions. Recent positive findings need confirmation in well-designed placebo-controlled randomized trials with large sample sizes.
Psychedelics like psilocybin and MDMA show promise as a new type of therapy for mental health disorders. Evidence suggests they may work with just one dose, produce rapid effects, and be effective for treatment-resistant conditions, possibly serving as a standalone treatment. More clinical trials are needed to test their safety, tolerability, and effectiveness in real-world patient populations.