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

This follow-up study (n=18) to Anderson and colleagues (2020) finds that attachment anxiety, but not attachment avoidance, decreased significantly 3 months after psilocybin-assisted group therapy.


“Attachment insecurity is determined early in life, is a risk factor for psychopathology, and can be measured on two separate continuous dimensions: attachment anxiety and attachment avoidance. Therapeutic changes toward more secure attachment correlate with reduction in psychiatric symptoms. Psilocybin-assisted psychotherapy has demonstrated promise in the treatment of psychopathology, such as treatment-resistant depression and substance use disorders. We hypothesized that psilocybin-assisted psychotherapy would reduce attachment anxiety and attachment avoidance, thus increasing attachment security. We also hypothesized that baseline measures of attachment insecurity, which can reflect a diminished capacity for trust and exploration, would inform the quality of the psilocybin 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.”

Authors: Christopher S. Stauffer, Brian T. Anderson, Kile M. Ortigo & Joshua D. Woolley


This is a three-month follow-up to an earlier study by Anderson and colleagues (2020) that studied demoralization in long-term AIDS patients in an open-label, group-therapy study.


Attachment theory describes how early formative infant-caregiver bonds translate into organized relationship patterns, or working models, in adulthood. Attachment security refers to an ability to seek support from trusted others, who act as a safe haven from distressing stimuli, and use emotionally intimate relationships as a secure base from which to explore the world.

Significant interpersonal experiences, such as skillfully delivered, typically long-term and intensive, psychotherapy interventions, can reduce symptoms of psychiatric disorders.

Psilocybin, an active component of “magic mushrooms”, has demonstrated potential for rapidly and durably enhancing psychological flexibility, and has been found to induce long-lasting changes in several domains of otherwise stable personality traits. It has been hypothesized that psilocybin-assisted psychotherapy will reduce attachment insecurity.

Baseline attachment variables may help predict important aspects of the psilocybin experience, including the strength of the psilocybin-occasioned mystical-type experience and the strength of challenging psilocybin experiences.

The present study incorporates data from a pilot study28 of psilocybin-assisted psychotherapy with a sample of 18 gay-identified, older, long-term AIDS survivors with moderate to severe demoralization. The study found that individuals with greater attachment security adjust better to a diagnosis of HIV or AIDS.

Change in Attachment Insecurity was observed from baseline to 3 months post-intervention. Attachment anxiety decreased by 4 points and attachment avoidance by 1.83 points.

Attachment insecurity was found to be a strong predictor of MEQ30 and ChEQ. Baseline attachment avoidance was also found to be strongly correlated with ChEQ.

We investigated the effects of psilocybin-assisted psychotherapy on attachment anxiety and attachment avoidance, and found that baseline attachment insecurity predicted the quality of the psilocybin experience itself.

Further exploration is required to better understand the mechanisms underlying our finding of reduced attachment anxiety. One possible explanation may be that psilocybin-induced plasticity31 triggers change in otherwise stable attachment-related neural pathways, or that mystical unity32 decreases an individual’s need for hyperactivating strategies.

Psilocybin has been found to increase connection to nature and to be among the most spiritually significant occurrences of people’s lives. This may be because psilocybin induces neural plasticity along with an experience of mystical unity, which reduces attachment anxiety.

We found that participants with attachment anxiety experienced notable reductions in demoralization, complicated grief, and post-traumatic stress after psilocybin administration, but not in attachment avoidance. This finding echoes previous patterns in the literature of significant reductions in attachment anxiety, but not attachment avoidance, after receiving psychotherapy.

The observed link between baseline attachment anxiety and strength of the mystical-type experience is another interesting finding requiring further exploration. Attachment disorganization may be a third dimension of attachment insecurity that may be related to the observed relationship between baseline attachment anxiety and strength of the mystical-type experience. Attachment disorganization is linked with dissociation, which is a trance-like state representing discontinuity between thoughts, actions, memories, surroundings, and sense of self. Dissociation might actually prime an individual for the healing potential of nonordinary states of consciousness.

Higher attachment avoidance predicted greater challenge during the psilocybin experience. Those who are more securely attached, or who have lower attachment anxiety and attachment avoidance, had milder mystical-type experiences as well as less challenging experiences.

We used the self-report ECR-M16 to measure attachment insecurity in gay, older, white, atheist, college-educated men, and found that psilocybin-induced changes were greater than changes induced by other aspects of the intervention, such as participants’ expectations or the group psychotherapy intervention.

A brief intervention of psilocybin-assisted group psychotherapy may improve attachment security in older long-term AIDS survivor men, and may have implications for improving attachment-related supra-diagnostic issues, such as interpersonal problems, difficulty with emotion regulation, and overall adaptive functioning.

The 16-item modified Experiences in Close Relationships scale (ECR-M16)46 measured attachment anxiety and attachment avoidance in participants at baseline, 3 weeks post psilocybin, and 3 months after the final group therapy session.

Participants completed the Mystical Experience Questionnaire (MEQ30) and Challenging Experience Questionnaire (ChEQ) the day after their psilocybin session. We used the MEQ30 total score, which comprises four factors: mystical (internal and external unity, noetic quality, and sacredness), positive mood, transcendence of time/space, and ineffability.

Author Contributions

C.S.S. conceptualized and conducted this analysis, B.T.A. designed and coordinated the parent trial, and K.M.O. provided guidance and clarity on attachment constructs.

Linked Research Papers

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Psilocybin-assisted group therapy for demoralized older long-term AIDS survivor men: An open-label safety and feasibility pilot study
This open-label feasibility study (n=17) showed that psilocybin-assisted group therapy (21-25mg/70kg) was safe and effective for the treatment of demoralization in older long-term AIDS survivors.

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