Results from a clinical phase II study suggest that psilocybin, a hallucinogenic chemical found in certain mushrooms of the Psiloybe genus, may benefit people with cancer and severe depression. Study participants treated with psilocybin not only experienced relief from their depressive symptoms, but also spoke highly of the therapy in the post-study survey. The findings are published by Wiley in two articles appearing online in *CANCER*, a peer-reviewed journal of the American Cancer Society.
By binding to a specific subtype of the serotonin receptor in the brain, psilocybin can cause mood, cognition, and perceptual disturbances. Psilocybin is currently classified as a Schedule I drug, meaning it has no recognized medical use and a high potential for abuse, and is not approved for clinical use by the US Food and Drug Administration. However, several randomized controlled trials have shown the safety and potential efficacy of psilocybin-assisted therapy – which combines psilocybin with psychological support from trained therapists – for treating severe depressive disorders. Ongoing research is also exploring the use of psilocybin-assisted therapy for various other mental illnesses, such as anxiety, addiction, and post-traumatic stress disorder.
In this latest open-label phase II study in adults with cancer and severe depression, 30 participants received a single dose of 25 mg of synthesized psilocybin at Sunstone Therapies in Rockville, Maryland, along with a 1:1 therapist session and group therapy support.
This study was distinctive because of its group-based approach. Cohorts of 3–4 patients were treated simultaneously with 25 mg psilocybin in adjacent, concurrently-opened spaces at a 1:1 therapist-to-patient ratio. The cohorts underwent therapy preparation as well as integration sessions following the psilocybin session as a group.“
Manish Agrawal, MD, Principal Investigator at Sunstone Therapies
Enrolled participants had moderate to severe depression scores at the start of the study. After eight weeks of treatment, Dr. Agrawal and colleagues observed that the severity of patients‘ depression decreased by an average of 19.1 points, a magnitude indicating that the majority no longer suffered from depression. Furthermore, 80% of participants showed sustained response to the treatment and 50% exhibited complete remission of depressive symptoms after one week, which lasted for eight weeks. Treatment-related side effects such as nausea and headaches were generally mild.
„As an oncologist, I have been frustrated for many years by not being able to offer a cancer treatment that addresses the whole person and not just the tumor,“ said Dr. Agrawal. „This was a small, open-label study, and more research needs to be done, but the potential is significant and could have an impact on helping millions of cancer patients who are also grappling with the serious psychological effects of the disease.“
Dr. Agrawal is also the principal author of a second study conducted under the direction of Yvan Beaussant, MD, MSc, from the Dana-Farber Cancer Institute, in which feedback from study patients was collected during exit interviews. Participants generally described positive experiences and noted that group affiliation calmed their anxieties and increased their readiness for therapy. Regarding therapeutic efficacy, they felt that the connection with the group deepened and enriched their experiences, ultimately contributing to their experience of self-transcendence and compassion for each other. Additionally, it was noted that the use of individual and group sessions supported the therapy in different ways. For example, conducting individual and group sessions allowed the therapy to remain an intimate, introspective process while also conferring a sense of „belonging.“
„As a hematologist, palliative care physician, and researcher, it was deeply moving and encouraging to witness the degree of improvement among the participants and the depth of their healing journey following their participation in the study. Participants expressed predominantly positive feelings about their experiences with psilocybin-assisted therapy, emphasizing the importance of the supportive, structured environment in which it took place,“ said Dr. Beaussant. „Many described a sustained transformative effect on their lives and well-being more than two months after taking psilocybin and felt better equipped to deal with cancer, and for some, end-of-life.“
Before this intervention is implemented in clinical practice, additional studies with a larger number of patients and a control arm should be conducted to compare its effects with other treatments or placebo.
„The acceptance of psilocybin-assisted group therapy in patients with cancer and severe depression: Qualitative analysis.” Yvan Beaussant, Elise Tarbi, Kabir Nigam, Skye Miner, Zachary Sager, Justin J Sanders, Michael Ljuslin, Benjamin Guérin, Paul Thambi, James A. Tulsky, and Manish Agrawal. CANCER; Online published: December 18, 2023 (DOI: 10.1002/cncr.35024).
URL upon publication: http://doi.wiley.com/10.1002/cncr.35024