Science Editorial – A single dose of dimethyltryptamine – the active ingredient in ayahuasca – and administered with psychological support quickly reduced depressive symptoms, according to a small clinical trial carried out with 34 adults with clinical depression.
Details are published in the magazine Nature Medicine and the improvements, which continued over the next two weeks, suggest that this short-acting treatment may be more practical than other longer-acting psychedelic therapies.
However, according to the authors, more and larger studies are necessary to confirm the effectiveness of dimethyltryptamine (DMT), which is behind the psychedelic effects of ayahuasca.
Major depressive disorder or clinical depression is one of the leading causes of disability worldwide, but many people do not respond to existing treatments, which are also associated with various side effects, such as sexual dysfunction, weight gain and sleep disorders.
Psychedelic-assisted therapy, including approaches using psilocybin (a compound found, for example, in hallucinogenic mushrooms), has shown promise. However, its psychedelic effects persist for about two hours, making therapeutic sessions long and difficult to extend, recalls a summary in the magazine.
In contrast, DMT is a fast-acting psychedelic molecule that, when administered intravenously, causes a brief period of subjective psychedelic effects, lasting about 30 minutes.
It was unclear whether such a fast-acting psychedelic could provide antidepressant effects similar to those of psilocybin.
To clarify this, the team led by David Erritzoe, from Imperial College London, carried out a phase 2 clinical trial in two stages, in which 34 adults with depression participated.
These were randomly assigned to receive DMT (17 of them) or a placebo in the first stage, which was blinded. Two weeks later an “open label” was carried out, in which volunteers and researchers knew what treatment was being administered (here DMT was given to all participants).
After two weeks, those who had received DMT in the first stage showed a greater reduction in depression scores on a clinical diagnostic tool called the Montgomery-Åsberg Depression Rating Scale, compared to those who had received the placebo. The improvements were already evident after a week.
During the open phase, the antidepressant effects lasted 12 weeks and no differences were observed in the scores of the aforementioned scale between people who had received one dose and those who had received two.
Most adverse effects were mild or moderate, such as infusion site pain, nausea, or temporary anxiety, and no serious treatment-related side outcomes were reported.
The authors note that larger studies are needed to confirm the effectiveness of DMT in the treatment of depression, the duration of its benefits, and its comparison with other existing therapies.