Persisting Reductions in Cannabis, Opioid, and Stimulant Misuse After Naturalistic Psychedelic Use: An Online Survey

Garcia-Romeu and colleagues situate their study within rising public-health concerns about cannabis, opioid, and stimulant misuse, noting that available treatments often produce limited long-term abstinence and that there are no approved pharmacotherapies for cannabis and stimulant use disorders. Earlier clinical and epidemiological studies as well as anecdotal reports have implicated serotonin 2A (5-HT2A) agonist psychedelics (for example LSD, psilocybin, and ayahuasca) in reductions in substance misuse, with the strongest randomized evidence historically for LSD in alcoholism and emerging pilot data for psilocybin in stimulant use disorders. The authors argue that naturalistic reports of substantial reductions in other drug use following psychedelic experiences have not been systematically documented for cannabis, opioids, and stimulants, creating a gap in the literature relevant to designing clinical interventions. The present study therefore aimed to characterise instances in which individuals reported lasting reductions or cessation of problematic cannabis, opioid, or stimulant use after taking a serotonin 2A agonist psychedelic in non-clinical settings. The investigators hypothesised that greater improvements in substance misuse would be associated with stronger mystical-type and insight experiences during the psychedelic session, consistent with prior clinical observations linking acute subjective effects to longer-term benefit. This work was framed as purposive, descriptive research to inform future clinical trials rather than as a test of causal efficacy.

The study used a cross-sectional, anonymous online survey hosted between October 2015 and August 2017, with recruitment targeted via social media and websites devoted to drug education and research. Inclusion criteria required participants to be aged 18 or older, fluent in English, to self-identify as having had problematic cannabis, opioid, or stimulant use, and to report a reduction or cessation of that problematic use following a serotonin 2A agonist psychedelic taken outside a research or medical setting. The survey purposely sampled individuals reporting positive outcomes after psychedelic use to describe such cases and to inform future clinical work. The Johns Hopkins Institutional Review Board approved the study; participants provided implied informed consent by completing the survey and received no financial compensation. Data collected included demographics, lifetime drug and psychiatric history, details of the specific psychedelic episode to which participants attributed their change in substance use (the "reference psychedelic experience"), and self-reported substance use before and after that experience. Substance use was assessed using adapted instruments: a modified Drug Use Disorders Identification Test-Consumption (DUDIT-C) to measure frequency/quantity/heavy use for the primary drug of concern, a modified DSM-5 Substance Use Disorder symptom checklist to classify SUD severity (2-3 symptoms = mild, 4-5 = moderate, ≥6 = severe), and a modified Alcohol Urge Questionnaire (labelled here Drug Urge Questionnaire) to assess craving. Participants also completed the MEQ30 to quantify mystical-type acute effects, and provided ratings of personal meaning, psychological insight, spiritual significance, challenge, and change in well-being attributed to the psychedelic experience. Analyses began with descriptive statistics and group comparisons (chi-square and one-way ANOVA) across substance groups (cannabis, opioids, stimulants). Change in overall substance consumption was indexed by DUDIT-C change scores (post minus pre). Pearson correlations examined associations between DUDIT-C change and variables such as dose, MEQ30 scores, personal meaning, and baseline consumption. Finally, a path analysis in MPlus tested a model in which pre-DUDIT-C predicted DUDIT-C change, dose predicted acute mystical and insight experiences, these acute experiences predicted personal meaning, and personal meaning predicted DUDIT-C change; age and intercorrelations among acute experiences were controlled. Maximum likelihood estimation with robust standard errors was used for the path model.

Of 3,987 people who began the survey, 2,556 met inclusion criteria and initiated a response; 630 completed the full survey for one of the three substance classes, and after excluding 186 whose reference psychedelic experience occurred within 3 months of survey completion the final sample comprised 444 adults. The sample was predominantly male (79.1%), white (82.4%), and from the United States (66.9%), with a mean age of 28.4 years (SD = 10.6). Participants identified their primary reduced substance as cannabis (n = 166), opioids (n = 155), or stimulants (n = 123). On average respondents reported 4.5 years (SD = 5.3) of problematic substance use prior to the reference experience and a mean age of first use of 17 years (SD = 4.4). High rates of psychiatric diagnoses were reported: about 62% reported an anxiety disorder and 62% a mood disorder; 60% reported a lifetime SUD not otherwise specified. Before the reference psychedelic experience, 95.7% of respondents met DSM-5 criteria for a substance use disorder (78.6% meeting criteria for severe SUD). Retrospective mean DUDIT-C score pre-experience was 8.0 (SD = 2.5). The psychedelic most commonly implicated in the reference experience was LSD (43%), followed by psilocybin (29%); reported dose levels were moderate for 47%, high for 33%, and very high for 12%. Most experiences occurred at home (59%) and were undertaken with psychological (61%) or spiritual (41%) intentions; only 14% reported intending specifically to reduce or quit substance use. On average participants rated the MEQ30 at about 67% of maximum, with roughly 40% meeting criteria for a "complete mystical experience." Most respondents rated the experience among the top 10 most personally meaningful or insightful of their lives, and 69% reported their sense of well-being or life satisfaction had increased "very much" as a result. Substance outcomes after the reference experience were notable: over 70% (n = 331) reported they had greatly reduced or quit using their primary substance. Mean DUDIT-C change score was -5.4 (SD = 3.2; range 4 to -12), and average post-DUDIT-C was 2.6 (SD = 2.8), a level below established AUDIT-C cutoffs for risky use for most respondents. Whereas 95.7% met SUD criteria before the psychedelic, only 27.3% met criteria in the period since the reference experience (mild 14%, moderate 5%, severe 8%). Most participants (63%) did not seek other formal substance-use treatment after the experience; some engaged in spiritual practices (16%), counselling (12%), or support groups (7%). Withdrawal and craving reports indicated that many respondents continued to experience withdrawal symptoms after the reference experience (for example depression, insomnia, craving), but substantial proportions reported these symptoms were "less" or "much less" severe than in prior quit attempts. Specifically, among those who had experienced craving previously, 56% of cannabis users reported craving to be much less severe after the psychedelic, while 75% of opioid users and 65% of stimulant users reported craving to be less or much less severe post-experience. Adverse effects were reported by 10% as definite and 9% as possible; 81% reported no persisting adverse effects. Five individuals (1.1% of the sample) described extremely severe persistent adverse reactions (for example prolonged nightmares, ongoing hallucinations or panic), and most of these five reported prior mental-health diagnoses. The path analysis supported the proposed model: higher pre-DUDIT-C predicted greater change in DUDIT-C (larger reductions), and higher psychedelic dose predicted stronger acute mystical and insight experiences. Both mystical and insight experiences predicted greater personal meaning, and higher personal meaning predicted larger reductions in substance use. Significant indirect effects were observed from mystical-type and insight experiences to DUDIT-C change via personal meaning (mystical: b = .02, SE = .01, p < .05; insight: b = .07, SE = .03, p < .05). Model fit indices indicated good fit (X2(7) = 10.13, p = .181; RMSEA = .03; SRMR = .040; TLI = .99). Group comparisons showed few demographic or clinical differences across cannabis, opioid, and stimulant subsamples, though cannabis users tended to be younger, less often from the U.S., have lower baseline distress and craving, lower MEQ30 scores, and smaller DUDIT-C change scores than opioid or stimulant users.

Garcia-Romeu and colleagues interpret their findings as descriptive evidence that many individuals who report problematic cannabis, opioid, or stimulant use experienced substantial and lasting reductions in use following a naturalistic serotonin 2A psychedelic experience. The majority of respondents retrospectively met criteria for severe SUD prior to the experience yet most no longer met SUD criteria in the period after it, and many reported persisting benefit for more than one year. The investigators highlight an association between higher psychedelic dose, stronger acute mystical and insight experiences, greater perceived personal meaning, and larger reductions in substance consumption, consistent with prior pilot clinical studies linking acute subjective effects to longer-term therapeutic outcomes. The authors acknowledge several important limitations that constrain interpretation. Data are anonymous, cross-sectional, and retrospective self-reports that cannot be verified and are subject to selection and recall biases; purposive sampling specifically solicited individuals reporting positive outcomes, so the sample does not provide prevalence estimates nor represent instances where psychedelics produced no change or worsening of substance use. Modified versions of alcohol-focused measures were used for other drug classes and have not been validated in that form. Adverse events were uncommon but included prolonged perceptual disturbances and persistent psychotic symptoms in a minority, emphasising risks associated with unsupervised naturalistic use compared with clinical administration with screening and support. In terms of implications, the authors position these results alongside prior epidemiological, preclinical, and pilot clinical data as further support for rigorous clinical research into psychedelic-assisted treatments for substance use disorders. They note potential psychological mechanisms identified in the survey—changes in life priorities or values, increased self-efficacy, reduced craving, and improvements in mood and anxiety—as plausible mediators of enduring behavioural change. Finally, the discussion calls for controlled clinical trials and federal funding to evaluate safety, efficacy, mechanisms, and therapeutic models for integrating serotonergic psychedelics into addiction treatment, while cautioning that psychedelics are unlikely to be a universal cure and that careful development is required.