DMT trial shows lasting depression benefit as broader psychedelic studies map shared brain changes
A 34-person trial found that a single 21.5mg intravenous dose of DMT with psychotherapy produced rapid antidepressant effects lasting three to six months. Separate brain-scan research across five psychedelics found a shared pattern of weaker within-network links and stronger communication between brain networks.
People with major depressive disorder can see a rapid and lasting improvement after a single dose of the psychedelic drug dimethyltryptamine (DMT) when it is combined with psychotherapy, doctors have said. A small clinical trial involving 34 people found that psychedelic-assisted therapy prompted a swift reduction in depressive symptoms that endured long after the drug had worn off, with some still feeling the benefits six months later.
The trial, reported in Nature Medicine, focused on people with moderate to severe treatment-resistant depression. One half received a single 21.5mg dose of DMT infused into a vein over 10 minutes. The other half received a placebo infused the same way. All of the participants had psychotherapy and follow-up assessments.
Patients given DMT improved significantly compared with the placebo group, as measured by scores on a standard depression questionnaire, with the antidepressant effects lasting from three to six months. In the second stage of the trial, all participants received a dose of DMT with therapy, but the researchers found no additional benefit in those who had two doses in total, suggesting a single dose may suffice. The trial was designed, funded and sponsored by Cybin UK, a neuropsychiatric firm.
At doses used in the trials, DMT induces a shorter but more intense trip than psilocybin, with the experience lasting about 25 minutes compared with a couple of hours for psilocybin. DMT is an active ingredient of the ayahuasca brew used in shamanistic rituals in South America.
Separate brain-scan research found that, in scans collected during treatments with psilocybin, LSD, mescaline, DMT, and ayahuasca, the same altered pattern kept reappearing. Researchers combined 11 datasets from five countries, analyzing more than 500 brain scans from 267 participants.
Under psychedelic drugs, many within-group links weakened, so networks that normally reinforce themselves held together less tightly. At the same time, links between different networks increased, letting sensory regions, decision circuits, and self-focused systems share more activity. Instead of a full breakdown, the strongest evidence points to increased communication between different brain networks.
Beyond the brain’s cortex, the most pronounced increases in connectivity involved the caudate and putamen. Effects in the thalamus appeared far less consistent than some smaller studies had suggested. Every dataset in the analysis came from healthy adults, so the results do not automatically translate to conditions like depression, addiction, or trauma.
The brain-scan analysis found a shared core pattern, not proof that every drug produces the same brain state. Different scanners, doses, and timing after dosing also varied, which can blur subtle effects even after careful data cleanup. The DMT depression trial was described as preliminary, but the results add to a growing body of evidence that psychedelic drugs, when coupled with psychotherapy, could help to alleviate depression in people who do not respond to existing antidepressants or therapies.