Psilocybin-Assisted Group Therapy and Attachment: Observed Reduction in Attachment Anxiety and Influences of Attachment Insecurity on the Psilocybin Experience

Attachment insecurity is determined early in life, isa risk factor for psychopathology, and can be measured on twoseparate continuous dimensions: attachment anxiety and attach-ment avoidance. Therapeutic changes toward more secureattachment correlate with reduction in psychiatric symptoms.Psilocybin-assisted psychotherapy has demonstrated promise inthe treatment of psychopathology, such as treatment-resistantdepression and substance use disorders. We hypothesized thatpsilocybin-assisted psychotherapy would reduce attachmentanxiety and attachment avoidance, thus increasing attachmentsecurity. We also hypothesized that baseline measures ofattachment insecurity, which can reflect a diminished capacityfor trust and exploration, would inform the quality of thepsilocybin session. Participants were male long-term AIDS survivors with moderate-severe demoralization (n = 18). Using the Experiences in Close Relationships scale, we measured attachment insecurity at baseline as well as immediately, and 3 months, after completion of a brief group therapy course, which included a single midtreatment open-label psilocybin session conducted individually. Clinically important aspects of the psilocybin session were assessed using the revised Mystical Experience Questionnaire and the Challenging Experience Questionnaire the day following psilocybin administration. Self-reported ratings of attachment anxiety decreased significantly from baseline to 3-months post-intervention, t(16) = −2.2; p = 0.045; drm = 0.45; 95% CI 0.01, 0.87. Attachment avoidance did not change significantly. Baseline attachment anxiety was strongly correlated with psilocybin-occasioned mystical-type experiences, r(15) = 0.53, p = 0.029, and baseline attachment avoidance was strongly correlated with psilocybin-related challenging experiences, r(16) = 0.62, p = 0.006. These findings have important implications for the general treatment of psychopathology as well as optimizing psilocybin-assisted psychotherapy as a broadly applicable treatment modality.