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

Attachment theory frames early infant–caregiver bonds as forming enduring working models of relationships in adulthood, which can be characterised along two continuous dimensions: attachment anxiety (worry about partner availability and desire for reassurance) and attachment avoidance (excessive self-reliance and intimacy evasion). While attachment security (low anxiety and avoidance) is protective against psychopathology, attachment insecurity predisposes people to conditions such as depression and substance use disorders. Working models are relatively stable but can shift following significant interpersonal experiences or intensive psychotherapy; therapeutic increases in attachment security frequently accompany reductions in psychiatric symptoms. Stauffer and colleagues situate psilocybin-assisted psychotherapy within this framework, noting prior evidence that psilocybin can produce rapid, durable changes in psychological flexibility, personality domains, and feelings of connectedness. They hypothesise that a brief course of psilocybin-assisted psychotherapy will reduce attachment insecurity (specifically attachment anxiety and attachment avoidance) and that baseline attachment insecurity will predict qualitative aspects of the psilocybin session, namely mystical-type and challenging experiences. The study uses data from a pilot open-label trial in older, gay-identified, long-term AIDS survivors with moderate–severe demoralization to explore these questions.

These exploratory analyses draw on an open-label clinical trial (n = 18) of psilocybin-assisted group psychotherapy for demoralization in older long-term AIDS survivor men (ClinicalTrials.gov NCT02950467); the primary clinical outcomes were reported elsewhere. Participants were described as gay-identified, older men with moderate–severe demoralization; the extracted text does not provide a full demographic table within the methods section. The intervention comprised four preparatory group therapy sessions, a single mid-treatment individual psilocybin session administered orally at 0.3–0.36 mg/kg (open-label), and four to six integrative group therapy sessions. Attachment insecurity was measured with the 16-item modified Experiences in Close Relationships scale (ECR-M16), a self-report tool adapted for older adults with chronic medical illness; assessments occurred at baseline, at the final week of group therapy (three weeks post-psilocybin), and three months after the final group session. The day after the psilocybin session participants completed the 30-item revised Mystical Experience Questionnaire (MEQ30, total score used) and the 26-item Challenging Experience Questionnaire (ChEQ, total score used). The MEQ30 captures mystical/internal and external unity, noetic quality, sacredness, positive mood, transcendence of time/space, and ineffability; the ChEQ captures grief, fear, death, insanity, isolation, physical distress, and paranoia. For statistical analysis the investigators applied the interquartile range rule to identify outliers and removed any observations outside median ±1.5×IQR; one outlier was removed for attachment anxiety. Two missing 3-month follow-up values (one each for attachment anxiety and avoidance) were imputed using the last observation carried forward from the three-week assessment. Standard descriptive statistics were reported. A paired-sample t-test compared baseline to three-month ECR-M16 scores, and repeated-measures standardised effect sizes (d rm ) with 95% confidence intervals were calculated. Pearson correlations examined relationships between baseline attachment dimensions and MEQ30 and ChEQ scores. Analyses used α = 0.05, no correction was made for multiple comparisons, the nested nature of the data was not modelled, and computations were performed in SPSS v26.0.

One outlier in attachment anxiety was identified and removed prior to analysis; demographic details are referenced as a table in the text but are not reproduced in the extracted material. Attachment anxiety showed a statistically significant reduction from baseline to three months post-intervention: mean change = −4 points, t(16) = −2.2, p = 0.045, d rm = 0.45, 95% CI 0.01 to 0.87. Attachment avoidance decreased by 1.83 points over the same interval, but this change was not statistically significant: t(17) = −0.9, p = 0.367, d rm = 0.19, 95% CI −0.22 to 0.59. Correlational analyses linked baseline attachment dimensions to acute psilocybin-session phenomenology. Baseline attachment anxiety correlated positively and significantly with MEQ30 total score (r(15) = 0.53, p = 0.029), indicating greater mystical-type experiences among those higher in attachment anxiety. Baseline attachment avoidance showed a small, nonsignificant negative correlation with MEQ30 (r(16) = −0.10, p = 0.693). Conversely, baseline attachment avoidance correlated positively and significantly with challenging experience intensity on the ChEQ (r(16) = 0.62, p = 0.006). The relationship between baseline attachment anxiety and ChEQ was small and not significant (r(15) = 0.18, p = 0.489). The investigators report these primary findings as: a significant reduction in attachment anxiety at three months post-intervention, no reliable change in attachment avoidance, and baseline attachment insecurity predicting different qualitative aspects of the psilocybin experience (attachment anxiety predicting mystical-type experiences; attachment avoidance predicting challenging experiences).

Stauffer and colleagues interpret their findings as preliminary evidence that a brief course of psilocybin-assisted group psychotherapy may reduce attachment anxiety but not attachment avoidance. They propose several possible mechanisms: psilocybin-induced neural plasticity altering attachment-related neural pathways, and psychological effects whereby intense mystical-type experiences (involving unity or interconnectedness) temporarily reduce the need for hyperactivating attachment strategies (proximity-seeking and reassurance-seeking) common in high attachment anxiety. The authors note that mystical experiences can be framed as connection to entities beyond the interpersonal (for example, nature or the transcendent), and suggest that such experiences might create a durable sense of security that outlasts the acute drug effects. The observed association between higher baseline attachment anxiety and stronger mystical-type experiences is discussed as counterintuitive to an alternative expectation that anxiety-driven proximity-seeking might distract from inward exploration. The authors reference work linking attachment disorganization and propensity for mystical experiences but acknowledge that the ECR-M16 does not assess disorganization; therefore, they could not examine that dimension. Regarding challenging experiences, the investigators argue that higher attachment avoidance—characterised by discomfort with vulnerability and reluctance to rely on others—may predispose participants to more difficult acute responses, since successful navigation of intense psychedelic sessions often requires surrender and trust in therapists. Several limitations are emphasised. The study lacked a control group, so changes in attachment cannot be ascribed to psilocybin specifically versus other elements of the intervention (expectancy effects or group psychotherapy). Generalisability is limited by the small, specific sample (older, gay-identified men who were largely white, atheist, and college-educated). Measurement relied on the self-report ECR-M16 rather than interview-based attachment assessments that capture disorganization. The analyses were exploratory, did not model nesting, and made no correction for multiple comparisons. The authors caution that attachment insecurity is not inherently pathological and may serve adaptive functions, and they note variability among participants in degree of change. Implications proposed by the investigators include the potential for psilocybin-assisted psychotherapy to foster attachment security, which could have transdiagnostic benefits for interpersonal problems, emotion regulation, and adaptive functioning. They recommend replication in larger, controlled trials, and suggest thorough attachment-informed clinical assessment, therapist self-awareness of attachment patterns, and strong co-therapy teams when working with vulnerable populations in psychedelic-assisted interventions.