The psychedelic component of magic mushrooms, psilocybin, could provide a new way to treat treatment-resistant depression, according to small-scale study.
In the study, led by Dr Robin Carhart-Harris from Imperial College London, and funded by the Medical Research Council (MRC), patients received 2 separate doses of psilocybin 7 days apart, together with psychological support. The findings, published in Lancet Psychiatry, revealed that 67% of patients were depression free one week after treatment, and 42% still in remission 3 months later. These patients had lived with depression for more than 18 years on average and had found no respite in any other treatment.
Previous studies have looked into the potential of using psychedelic drugs for conditions such as end of life anxiety, obsessive-compulsive disorder and smoking dependence. Psilocybin acts on the serotonin system suggesting it could be developed for use in the treatment of depression. The study aimed to assess safety and whether a potential treatment dose of psilocybin could be tolerated.
Hallucinogenics such as psilocybin can cause unpleasant reactions, including anxiety and paranoia, so it is important to establish whether the drug can be administered safely to people with depression. To investigate the safety and feasibility of using psilocybin for treatment-resistant depression, researchers from Imperial College London conducted a strictly monitored feasibility study. As this was not a randomised-controlled trial, the patients knew they were receiving the drug and there was no control group to provide comparison either with existing treatments or with no treatment at all.
Twelve people with moderate to severe treatment-resistant depression who had not responded to at least two courses of antidepressants were recruited (6 men and 6 women, aged 30-64). Most of the participants volunteered to take part following presentations by the researchers and media coverage.
Eleven participants had previously undergone psychotherapy. The volunteers went through a thorough screening process before they were allowed to participate. Criteria used to rule out participants from taking part included people with a history of suicide attempts, those with diagnosis of a psychotic disorder and other significant medical conditions. Participants were fully supported at all times before, during and after they received psilocybin.
The psilocybin was administered to the participants at a research facility and participants were monitored by at least two members of clinical staff at all times during the psilocybin administration sessions. There was a follow-up with patients the next day, and then 1, 2, 3 and 5 weeks after the second dosing session.
Blood pressure, heart rate and the self-reported intensity of the effects of psilocybin were monitored before and continuously during each dosing session. No serious unexpected side effects were reported during the study. All participants reported temporary anxiety before and during initial drug administration.
All patients showed some decrease in symptoms of depression for at least three weeks. Seven of them continued to show a positive response 3 months after the treatment, with 5 remaining in remission after 3 months.
The authors acknowledged the study had some limitations, in addition to the small sample size. Previous studies have shown that using psychedelics can leave one open to suggestion, which could have been part of the positive outcomes seen here. It was also not possible to control for the psychological support received throughout this study.
Dr Carhart-Harris said: “Psychedelic drugs have potent psychological effects and are only given in our research when appropriate safeguards are in place, such as careful screening and professional therapeutic support. I wouldn't want members of the public thinking they can treat their own depressions by picking their own magic mushrooms. That kind of approach could be risky.”
Senior author, Professor David Nutt, also of Imperial College London, added: “It is important that academic research groups try to develop possible new treatments for depression as the pharmaceutical industry is pulling out of this field. Our study has shown psilocybin is safe and fast acting so may, if administered carefully, have value for these patients.”
Dr Louise Jones, head of translational research at the MRC, said: “We currently don’t have effective treatments for some people’s depression so we need to know more about how drugs such as psilocybin could be used for patient benefit. This study showed that, with appropriate safeguards, psilocybin can be safely administered to some patients with treatment-resistant depression. It will now be important to undertake studies that evaluate its role as a potential treatment.”
Amanda Feilding, study author and co-director of the Beckley/Imperial Research Programme, said: “It is very exciting that our latest psilocybin study paves the way for a new treatment for depression. For the first time in many years, people who were at the end of the road with currently available treatments, reported decreased anxiety, increased optimism and an ability to enjoy things. This is an unparalleled success and could revolutionize the treatment of depression.”
Beckley/Imperial's former studies with psilocybin showed that while under the effects, there is a disruption of connectivity in the default mode network, a network responsible for maintaining the sense of self, which has been shown to be hyperactive in major depressive disorders. The studies also revealed that psilocybin enhances autobiographical memory recollection, indicating its usefulness in psychotherapy, both as a tool for memory recall and to disrupt fixed negative patterns of thought.
An integral component of the psilocybin-assisted psychotherapy is music. Beckley/Imperial’s previous studies with LSD have shown that music works in synergy with psychedelics, and intensifies and deepens emotional experience which can catalyse the healing process.