A single dose of DMT given alongside psychotherapy has been shown to ease symptoms of major depression, with benefits lasting for months, according to a small clinical trial.
The trial found that people receiving the psychedelic treatment saw rapid improvements in depressive symptoms, which continued well beyond the short period during which the drug was active.
Researchers studied 34 people with moderate to severe treatment-resistant depression, meaning their condition had not improved after trying at least two antidepressants.
An estimated 100m people worldwide live with treatment-resistant depression, and around half are unable to carry out routine daily tasks.
Participants were randomly assigned to receive either a single 21.5mg dose of dimethyltryptamine, known as DMT, delivered through a vein over 10 minutes, or a placebo.
All participants also received psychotherapy and follow-up assessments.
Those who received DMT showed a greater reduction in depression scores than those given placebo, based on a standard clinical questionnaire.
The improvement was still evident between three and six months after treatment.
DMT is a psychedelic compound found in the ayahuasca brew traditionally used in South American rituals.
It can cause intense but short-lived changes in perception, including altered sense of time and self. At the dose used in the trial, its effects lasted around 25 minutes, compared with several hours for psilocybin, the active compound in magic mushrooms.
In the second phase of the study, all participants were given DMT with psychotherapy.
Researchers found no additional benefit among those who received a second dose, suggesting one session may be sufficient.
Dr David Erritzoe, a psychiatrist and the study’s lead investigator, said: “There is an immediate antidepressant effect that is significantly sustained over a three-month period and that’s exciting because this is one session with a drug, embedded in psychological support.”
Psychedelic drugs are thought to support psychotherapy by helping people step out of rigid or unhelpful thinking patterns.
Erritzoe compared the effect to shaking snow on a mountain: “You redistribute the snow so it’s easier to take new tracks, and at the same time it becomes easier to take new routes because the landscape has been flattened.”
Because a DMT experience is much shorter than that of psilocybin, it could be easier for clinics to deliver, although patients may need additional support to recover from particularly intense experiences.
The findings follow earlier positive trials of psilocybin, which have fuelled expectations that psychedelic-assisted therapies could be approved for treating depression in the UK later this year.
If approved, they are expected to be available initially through private clinics.
The Feilding commission was established last year to help guide the safe and ethical introduction of psychedelic-assisted therapies, amid concerns that commercial pressures could compromise patient safety.
Dr James Rucker, a consultant psychiatrist who worked on earlier psilocybin research, said: “Quite how these drugs will fit in this world of financial austerity, stigma and opprobrium towards anything that has the word psychoactive in it, I don’t know.
“It’s interesting to be a part of, but I can’t call it.”
