Several studies have shown positive effects for intractable depression, including with psilocybin, which is found in so-called magic mushrooms. Now British researchers have investigated the hallucinogenic substance DMT, which is part of the psychoactive herbal brew ayahuasca.
In the study, published in the journal Nature Medicine, 34 adults were given either DMT intravenously or a placebo. After two weeks, 35 percent of the participants who received DMT had halved their depression symptoms, compared to 12 percent in the placebo group.
Intravenous DMT produces a much shorter psychedelic experience than psilocybin. DMT is rapidly eliminated from the body, and its apparent effect lasts a few minutes rather than several hours. This could make it easier to handle and administer in healthcare settings. In studies on psilocybin, patients need to remain in the clinic for a full day.
Need alternatives
Mikael Tiger, senior physician and associate professor of psychiatry who researches psilocybin for depression at the Karolinska Institute, says that the study is interesting but that the observation period for the placebo group is short.
After two weeks, DMT has a better effect than placebo, but we would like to know how long the difference lasts.
He welcomes studies on treatments aimed at people with difficult-to-treat depression.
Many are helped by psychotherapy or medication, but not all. For them, multiple options are needed.
More studies are needed
One challenge with studies of psychedelic substances is that it becomes clear who is receiving a placebo - it is difficult to achieve a "fake high".
In the current study, all participants were also offered the opportunity to take DMT two weeks after the first dose.
It is understandable that this is done from an ethical perspective, since patients are often disappointed if they receive a placebo, but it ruins the scientific comparison over time. I would have liked to have seen them wait at least six weeks before offering all participants DMT.
The study is a phase II trial. The researchers write that more and larger studies are needed to further investigate the effect.
