A single dose of dimethyltryptamine (DMT), a psychedelic compound found in ayahuasca, significantly reduced symptoms of depression in a trial of 34 participants, researchers at Imperial College London have found. The results, published in the journal Nature, suggest a potential new avenue for treating the condition, which affects an estimated 332 million people globally, according to the World Health Organization.
The phase 2a clinical trial randomised 17 participants to receive 21.5 milligrams of DMT intravenously, while the remaining 17 received a placebo. All participants received psychotherapeutic support alongside the infusion. After two weeks, those who received DMT demonstrated a substantially greater reduction in depressive symptoms compared to the placebo group, with improvements sustained for up to three months.
DMT’s relatively short duration of action – a half-life of approximately five minutes due to rapid metabolism – is a key advantage, researchers noted. This allows for shorter therapeutic sessions, potentially lowering costs and improving accessibility for patients. The trial participants had lived with depression for an average of 10.5 years prior to the study.
The study reported that DMT was well-tolerated, with no serious adverse events. The most commonly reported side effect was pain at the injection site.
While the findings are encouraging, independent experts caution that further research is essential. James Stone, professor of psychiatry at Brighton and Sussex Medical School, highlighted the potential for negative experiences during psychedelic sessions. “There may be a risk of negative experiences during the psychedelic experience that could be frightening or traumatising,” Stone said, adding that certain individuals may be more vulnerable to such effects and require careful screening.
Current treatments for depression, primarily antidepressant medications and psychotherapy, often prove insufficient for many patients. Response rates for antidepressants range between 40 and 60 percent, and 20 to 30 percent of individuals with major depressive disorder (MDD) develop treatment-resistant depression, failing to respond to at least two different medications. This unmet need has spurred interest in exploring alternative treatments, including psychedelics.
Currently, no psychedelic treatments, including DMT and lysergic acid diethylamide (LSD), have received full marketing authorisation from the European Medicines Agency for clinical use. Access is largely limited to research trials and compassionate use programmes. However, the Czech Republic recently legalised medical psilocybin – the active compound in “magic mushrooms” – for psychotherapy, effective January 1, 2026. The treatment is available to patients with treatment-resistant depression or mental deterioration related to cancer or other life-threatening conditions, and must be administered by certified professionals in approved facilities.