American researchers have reported the success of the second phase of clinical trials of combined individual and group psilocybin psychotherapy for the treatment of major depression in cancer patients. A report on the work was published in the journal Cancer, and a separate publication in the same journal is dedicated to the study of subjective the perception of such treatment.

Depression often accompanies cancer, with clinically significant manifestations observed in one out of three to four patients. At the same time, the traditional approach to treatment, including psychotherapy and the prescription of antidepressants, is often insufficiently effective. Due to this, psychedelic psychotherapy, including the use of psilocybin, is of great interest, as it has repeatedly demonstrated high effectiveness in clinical trials in the treatment of major depressive, post-traumatic stress and other mental disorders.

Thirty cancer patients (average age 56) took part in the open (non-blind) phase II clinical trials conducted by Sunstone Therapies CEO Manish Agrawal and colleagues from several US research centers. Two-thirds of them were between one and four years old after diagnosis; 53.3 percent had metastatic and inoperable disease. Breast cancer was the most common cancer (33.3 percent), followed by leukemia and lymphoma (26.7 percent). All participants had moderate to severe major depressive disorder without psychotic features (HAM-D score of 18 or more). At the time of enrollment, they were not taking antidepressants, antipsychotics, or medical cannabis.

After interviews, physical examinations, and screening tests, each participant was assigned an individual psychotherapist and had two orientation sessions, which included information about psilocybin therapy. After that, they participated in weekly therapy sessions with 25 milligrams of synthetic psilocybin for eight weeks. During these sessions, the drug was administered simultaneously to three to four patients who were in adjacent rooms of a public cancer center alone with their psychotherapist for 4.25 hours, after which they were united for 3.75 hours for group support and integration of the gained experience.

The dynamics of the severity of depression during therapy was assessed using the MADRS scale. At the eighth week, it decreased by an average of 19.1 points (p < 0.0001) compared with the initial level. A stable response to treatment was observed in 80 percent of participants; exactly half achieved complete remission of depressive symptoms in the first week, which was maintained throughout the study. No severe side effects were registered. Some patients complained of moderate and transient nausea and headache. Laboratory tests and ECG were normal. The participants did not show any suicidal tendencies.