A single dose of psilocybin combined with psychotherapy produced sustained reductions in depression and anxiety symptoms among patients with cancer 2 years after treatment, according to new research.
The study included 30 adults with cancer andmajor depressive disorder who were not taking antidepressants, antipsychotics, or medical cannabis at enrollment. Participants had no suicide risk and were treated in a community cancer care setting. All received a 25-mg dose of psilocybin during a 6- to 7-hour monitored session, along with preparatory and integration psychotherapy sessions.
Researchers assessed mental health outcomes at 2, 18, and 24 months after treatment. Depression was measured using the Montgomery Åsberg Depression Rating Scale (MADRS), and anxiety was measured using the Hamilton Anxiety Rating Scale (HAM-A).
At 2 months, 89.3% of patients showed statistically significant reductions in depression symptoms, defined as at least a 50% decrease in MADRS scores, with an average reduction of 20 points from baseline. At 24 months, 53.6% of patients continued to show significant reductions, averaging a 15-point decrease from baseline. Half of the participants also achieved sustained reduction and remission of depression symptoms at 2 years.
Anxiety results followed a similar pattern. At 2 months, 78.6% of participants showed significant anxiety reduction, with an average HAM-A decrease of 17 points. At 24 months, 46.4% maintained significant reductions, averaging a 13.9-point decrease. Sustained anxiety reduction was seen in 42.9% of participants at 24 months.
Some participants maintained these benefits without additional treatment. Twenty-five percent achieved sustained depression reductions without further antidepressant or psychedelic therapies. Another 25% received antidepressants after psilocybin, and a subset also received additional psychedelic therapy.
The cohort had a median age of 57.5 years, ranging from 30 to 78 years. Two-thirds were female, and nearly 79% were White. At enrollment, 60.7% were not taking psychiatric medications, and 60.7% had no prior psychedelic use. Alcohol consumption decreased for 21.4% following treatment.
No patients were hospitalized for depression during the 24-month follow-up, and safety outcomes were favorable.
Previous studies have shown limited long-term effectiveness for antidepressants in cancer patients. Traditional treatments, including selective serotonin reuptake inhibitors, demonstrated only modest benefits within 6 to 12 weeks, with no available long-term data. This study adds new long-term findings on psilocybin-assisted therapy for mental health conditions in cancer patients.
Further research is underway to better define psilocybin’s role, refine therapy protocols, and identify which patients may benefit most.
The study was conducted under institutional review board oversight, with informed consent from all participants. Funding was provided by private sponsors and philanthropic support.
Manish Emanuel reported personal fees, speaking engagements, board memberships, and advisory roles with numerous organizations, including UnitedHealth Group, the World Health Organization, and several academic and healthcare institutions. Manish Agrawal, Kim Roddy, Betsy Jenkins, and Celia Leeks are employed by Sunstone Therapies. Full disclosures are available in the original publication.
Source: ACS Journals