Therapeutic emergence of dissociated traumatic memories during psilocybin treatment for anorexia nervosa.

Background: Psychedelic treatment is a rapidly emerging therapeutic approach for a host of chronic, difficult to treat psychiatric disorders, including anorexia nervosa (AN). Trauma and its sequelae, such as dissociation, often contribute to comorbidity and treatment refractoriness.

Aims: In this report, we describe the therapeutic emergence of previously dissociated traumatic memories of sexual assault in 2 of 10 research participants with AN while receiving psilocybin treatment.

Methods: Ten female adults who met DSM-5 criteria for AN or pAN (partial remission) participated in an open pilot study evaluating the safety, tolerability and preliminary efficacy of psilocybin-assisted psychotherapy. Participants received a 25-mg dose of investigational drug COMP360, a proprietary pharmaceutical-grade synthetic psilocybin formulation developed by COMPASS Pathfinder Ltd. administered in conjunction with psychological support. Participants also received two integration therapy sessions on days 1 and 7 after dosing, and they were reassessed at 1 and 3 months. Participants were interviewed using a semi-structured interview to understand qualitative perspectives of treatment and its effect on AN.

Results/outcomes: Both patients described in this report significantly benefited from the emergence and processing of previously dissociated information (dissociative amnesia), and both patients subsequently attained remission of their AN psychopathology at 3-month follow-up as determined by global scores on the Eating Disorder Examination Questionnaire (EDE-Q) and clinically meaningful weight gain.

Conclusions/interpretation: PT may hold promise not only in the treatment of eating disorders but also trauma-related disorders, including PTSD and dissociative amnesia. Potential mechanisms of psilocybin's facilitation of remembering and processing traumatic material is reviewed.