A new study indicates that reductions in experiential avoidance play a significant role in the therapeutic effects of psilocybin-assisted therapy among depressed patients, leading to improvements in well-being and reductions in depression severity, anxiety, and suicidal ideation. The findings, published in the Journal of Affective Disorders, highlight the importance of experiential avoidance as a potential mechanism underlying the positive effects of psilocybin therapy.
Experiential avoidance refers to a psychological tendency where individuals try to avoid or escape from unpleasant or distressing thoughts, emotions, sensations, or experiences. It involves a deliberate effort to avoid, suppress, or distract oneself from uncomfortable or distressing internal experiences.
Psilocybin is a naturally occurring psychedelic compound found in certain species of mushrooms, commonly referred to as “magic mushrooms.” It is a potent psychoactive substance that interacts with serotonin receptors in the brain, leading to altered perception, cognition, and mood.
The researchers, Richard Zeifman and his colleagues, were interested in conducting this particular study because there is a growing body of research supporting the potential therapeutic benefits of psilocybin-assisted therapy. This type of therapy involves the administration of psilocybin alongside psychological support as a novel mental health intervention.
Previous studies have suggested that psilocybin therapy may have positive effects on various mental health outcomes, including reducing anxious and depressive symptoms, addressing suicidal ideation, and enhancing overall well-being. However, there is still a need to understand the specific mechanisms underlying its therapeutic effects.
“Psilocybin therapy is showing promise for a wide range of mental health challenges (ranging from major depression to alcohol use disorder), leaving open the question of why/how it works and whether it works differently than other pharmacological interventions,” explained Zeifman, a postdoctoral fellow in the NYU Langone Centre for Psychedelic Medicine at the NYU Grossman School of Medicine.
“Based on descriptions of participants experience with psilocybin therapy in previous trials, we were interested in testing whether psilocybin therapy led to improvements in mental health by allowing individuals to shift from avoiding their emotional experiences to being open to them and whether this was specific to psilocybin therapy (relative to escitalopram, a selective reuptake inhibitor).”
Zeifman and his colleagues conducted their analyses using data from a clinical trial that recruited 59 participants who met specific inclusion criteria, including having an diagnosis of major depressive disorder, moderate to severe depression severity, and proficiency in the English language. The participants were randomly assigned to one of two conditions: the psilocybin therapy condition or the escitalopram condition.
In the psilocybin therapy condition, participants received two large doses of psilocybin (25 mg) three weeks apart and six weeks of daily inactive placebo. In the escitalopram condition, participants received two very low doses of psilocybin (1 mg) three weeks apart and six weeks of daily escitalopram (an antidepressant). The study was conducted as a double-blind randomized controlled trial, meaning neither the participants nor the researchers were informed about which treatment they would receive.
All participants received psychotherapeutic treatment, including preparation sessions, dosing sessions, and integration sessions. The preparation sessions aimed to establish rapport with the therapists, discuss the importance of engaging with difficult emotions, and set therapeutic intentions for the dosing sessions.
Dosing sessions followed traditional guidelines for psilocybin therapy, with participants lying down in a comfortable room, wearing an eyeshade, and listening to music. Two therapists were present to provide support and guidance during the experience. Integration sessions helped participants translate insights from their psilocybin experience into their daily lives and promote behavioral change.
Various measures were used to assess mental health outcomes, experiential avoidance, and connectedness. These measures were administered at baseline and six weeks after the start of the treatment.
Zeifman and his colleagues found that reductions in experiential avoidance were associated with improvements in mental health outcomes in the psilocybin therapy condition. Participants who received psilocybin therapy experienced a significant reduction in experiential avoidance over time.
They also showed that reductions in experiential avoidance predicted improvements in well-being, depression severity, suicidal ideation, and trait anxiety. The relationship between experiential avoidance and mental health outcomes was mediated by increased connectedness and experiences of ego dissolution and psychological insight.
“Experiences of ego dissolution (i.e., a breakdown of one’s sense of self) and psychological insights derived from the experience were strongly associated with reductions in experiential avoidance following psilocybin therapy,” Zeifman told PsyPost. “These findings suggest that the psilocybin experience, and lessons learned from the experience may play important roles in explaining psilocybin therapy’s therapeutic potential.”
In contrast, in the escitalopram condition, there was no significant reduction in experiential avoidance over time. However, participants in this condition still experienced increases in well-being and decreases in depression severity and anxiety. Changes in experiential avoidance did not predict changes in mental health outcomes in the escitalopram condition.
“Our findings suggest that psilocybin therapy may be helpful because it gives people the opportunity to confront and work through challenging experiences rather than run away from or avoid them,” Zeifman explained to PsyPost.
“By helping people to reduce their rigid avoidance of difficult emotional experiences, psilocybin therapy may allow for an increased sense of connectedness (to one’s self, others, and the world) and thereby to improved well-being and mental health. It is notable that reducing emotional avoidance played a central role within psilocybin therapy, but not escitalopram, suggesting that psilocybin therapy may improve mental health through different mechanisms than traditional pharmacological interventions for major depression.”
The new findings build upon Zeifman’s previous research, based on two online surveys, which provided evidence that psychedelic drugs can improve mental health by making individuals more accepting of distressing experiences. But the present study has some limitations that should be considered.
“Our findings are limited by the use of self-report methods and a relatively small homogenous sample,” Zeifman said. “There is a need for further research that is less reliant on self-report and in samples that are more diverse and with mental health concerns that extend beyond major depression.”
The paper, “How does psilocybin therapy work? An exploration of experiential avoidance as a putative mechanism of change“, was authored by Richard J. Zeifman, Anne C. Wagner, Candice M. Monson, and Robin L. Carhart-Harris.
