A study published in Scientific Reports found that first-time users of psychoactive brew ayahuasca showed decreases in psychopathology and depression one month and six months later. [..]

Due to participant drop-out, 28 of the subjects participated in a follow-up one month after attending the ayahuasca ceremony. Out of the 18 subjects who met criteria for a psychiatric disorder at the start of the study, 61% no longer met criteria at the one-month assessment and 22% met criteria for fewer disorders. Only one participant who had no diagnosis at baseline newly met criteria for a disorder, which was generalized anxiety disorder. Furthermore, participants showed reduced scores in anxiety and hostility.

Next, 15 subjects participated in a 6-month follow-up. The drop in depression scores now reached statistical significance. Interestingly, although anxiety and hostility had improved at the one-month mark, these assessments did not improve at the 6-month mark. “This pattern,” the researchers say, “suggests that the potential therapeutic benefits of ayahuasca are temporary and do not persist in time, excepting for the case of depression . . . This may suggest that the long-term benefits of ayahuasca use depend on maintaining regular use.”

As a comparison group, a separate sample of 23 regular users of ayahuasca was additionally recruited. These experienced users had attended an average of 70 ayahuasca ceremonies and were asked to complete the same assessments as the first-time users. A comparison between the two groups showed no differences except that long-term users showed lower depression scores, a finding that researchers note is “consistent with the long-term antidepressant effects of ayahuasca.”

“Despite not finding statistically significant differences between assessments among the sub group of naïve users with psychiatric disorders,” the authors say, “remarkable improvements were observed for several scales measuring psychopathology and quality of life. This lends support to previous research that found that ayahuasca users gained therapeutic benefits or experienced an enhanced ability to solve personal problems.”