REAL-WORLD EVIDENCE FROM LEGAL PSILOCYBIN-ASSISTED SERVICES IN OREGON: PSYCHEDELIC PREPAREDNESS AND EXPERIENTIAL PREDICTORS OF MENTAL HEALTH OUTCOMES

Background

Psychedelic-assisted therapies are gaining increasing attention as clinical trials report beneficial effects across psychiatric conditions. In parallel, regulatory landscapes are shifting, with facilitated psilocybin sessions now legally available in Oregon. As access expands, there is a growing need to better understand and predict psychedelic experiences to mitigate risk and optimize therapeutic benefits. Accumulating evidence suggests that qualitative features of the acute psychedelic experience are associated with downstream positive and negative mental health outcomes. Psychological “pre-state,” including set, intention, and therapeutic rapport, has emerged as a modifiable determinant of post-session outcomes. The Imperial Psychedelic Predictor Scale (iPPS) is a validated self-report instrument designed to operationalize these constructs and predict features of the acute psychedelic experience. To date, the relationship between iPPS domains and mental health outcomes in real-world legal psychedelic services has not been examined.

Methods

The current study was a naturalistic, IRB-approved observational study of adults who completed a psilocybin session at licensed service centers in Oregon. Eighty-eight participants completed validated self-reported outcome measures at two timepoints: baseline (pre-session) and 30 days post-session. Outcomes included depressive symptoms (Patient Health Questionnaire-8), anxiety symptoms (Generalized Anxiety Disorder-7), and psychological wellbeing (World Health Organization - Five Well-being Index). Experiential predictors were measured using the iPPS, including subscales assessing psychological set, intention, and therapeutic rapport. Linear mixed-effects models were fit separately for each outcome, including fixed effects for timepoint and iPPS subscales, and a random intercept for participants. These models were specified to examine process-level associations while adjusting for overall change over time.

Results

Timepoint was a significant predictor across all models, reflecting overall improvements in depression, anxiety, and well-being following a psilocybin session. Beyond these temporal effects, select iPPS domains were independently associated with mental health outcomes. Higher Intention scores (clarity of personal intention for the experience) were associated with lower depressive symptom severity (b = −0.11, p = 0.03). For anxiety, both Intention and Feeling (positive perceived relationships with others present during the session) were associated with lower symptom severity (Intention: b = −0.10, p = 0.03; Feeling: b = −0.21, p = 0.04). No iPPS domains were significantly associated with well-being.

Discussion

Beyond overall symptom improvement over time, clarity of intention and positive therapeutic relationships were independently associated with lower depression and anxiety severity, highlighting these factors as key process-level correlates. Interestingly, positive therapeutic relationships emerged as a significant correlate only in the anxiety model, which may indicate that interpersonal safety and rapport are especially relevant for anxiety-related symptom processes. IPPS domains capturing these constructs may serve as meaningful indicators of psychological context and offer actionable targets for optimizing preparation practices and social context within real-world legal psychedelic care models.