At Medical News Today, we have reported on a range of studies that pointed to psilocybin — the psychoactive substance in "magic mushrooms" — as a potential remedy for depression.
Two such studies showed that the psychoactive compound can reduce feelings of anxiety and depression in people with advanced cancer, while another small trial suggested that the compound could succeed where previous depression treatment has failed.
Treating depression can be challenging not only because some depression types are treatment-resistant, but also because existing therapies have a range of unwanted side effects.
A new study — which was carried out by researchers at Imperial College London (ICL) in the United Kingdom — suggests that magic mushrooms could treat depression while avoiding these side effects.
The new research consists of two studies, both of which were led by Leor Roseman, a member of the Psychedelic Research Group at ICL.
Participants felt 'emotionally reconnected'
In the first study, published in the journal Neuropharmacology, 20 people diagnosed with moderate to severe depression that conventional treatment had not alleviated participated in two dosing sessions with the magic mushroom compound.
Using functional MRI (fMRI), the team scanned the brains of the participants while they looked at pictures of emotive expressions. The scans were taken before and after each drug intervention.
In order to assess the impact of the treatment on depression, the subjects were all provided with psychological support before, during, and after the intervention.
After the treatment, the participants reported feeling better, "emotionally re-connected, and accepting."
The fMRI scans also revealed a stronger brain response to emotive faces. Specifically, the scientists saw more activity in the brain's amygdala, which is an emotion-processing area associated with depression. The study authors explain:
"Based on the present results, we propose that psilocybin with psychological support is a treatment approach that potentially revives emotional responsiveness in depression, enabling patients to reconnect with their emotions."
Roseman comments on the new findings, saying that they "are important as they reveal biological changes after psilocybin therapy and, more specifically, they suggest that increased emotional processing is crucial for the treatment to work."
But the authors also caution that more research is needed to establish firmly whether the positive effects were due to the psychoactive compound itself, the psychological counseling, or the interruption of the antidepressant treatment the subjects had been on before the study.
"Having a healthy control group in future studies should be helpful in answering some of these questions," Roseman admits.
'Mystical experience' improves efficacy
The second paper, published in the journal Frontiers in Pharmacology, examined whether or not the quality of the psychedelic experience was linked with the success of the treatment.
Roseman and colleagues gave questionnaires to another group of 20 volunteers who underwent two treatment sessions with psilocybin.
The researchers looked at the so-called feeling of oceanic boundlessness, which is a "mystical-type experience" involving feelings of unity and a lack of boundaries between the self and the universe.
The study revealed that the more strongly the participants felt this experience, the better was their mental health in the long-term.
Depressive symptoms subsided, and the mental benefits lasted for weeks after the treatment in participants who reported a strong mystical experience.
"[F]uture therapeutic work with psychedelics may consider investigating ways which enhance mystical-type experience and reduce anxiety, given the growing evidence that this serves the efficacy of the treatment model," conclude the authors.
Directions for future research
The researchers are planning on carrying out larger trials with a healthy control group in which the effects of psilocybin could be compared with an existing antidepressant.
"We also want to investigate how the amygdala responds a longer time after treatment," Roseman adds, "which will inform us about longer-term effects — compared to the [first] study, which was only looked at 1 day after the therapy."
Additionally, in light of the findings of their second study, the group recommends that future trials with psychedelics should aim to enhance the "mystical" aspect of the experience.