Classic psychedelics in the treatment of substance use disorder: Potential synergies with twelve-step programs

The extracted text does not present a formal Methods section or a reported systematic search strategy. Rather, the paper is a narrative review and conceptual analysis that draws on multiple sources: early and contemporary clinical trials, single-arm pilot studies, survey and epidemiological data, anthropological and observational reports, and historical documentation regarding Bill Wilson and AA. Key study examples, pooled historical trial data, and ongoing trial identifiers are cited to illustrate empirical points. Because no explicit inclusion/exclusion criteria, databases searched, or quality-assessment methods are described in the extracted text, the reader should treat this as a selective, interpretive review rather than a systematic meta-analysis. The authors integrate clinical trial results (both randomized and open-label), observational and survey findings, and cultural/ethnographic evidence to evaluate therapeutic potential, mechanisms (notably mystical or self‑transcendent experiences), safety considerations, and possible synergies or tensions between classic psychedelic treatments and TSF programmes.

The review summarises evidence across several substances of addiction and study types, reporting both controlled trials and observational findings. Safety and mechanism: Classic psychedelics that act primarily at the serotonin 2A receptor (5-HT2A) — including psilocybin, LSD, mescaline and DMT/ayahuasca — are described as having low physiological toxicity and low addictive potential, typically producing only transient cardiovascular changes. The authors note clinical screening and supervision mitigate many recreational-use risks. Several clinical studies link the intensity of mystical or self‑transcendent experiences to better treatment outcomes, suggesting these subjective effects may be an active therapeutic component. Alcohol use disorder (AUD): A historical meta-analysis of six randomized controlled LSD trials from 1966–1970 (pooled N = 536; median LSD dose 500 mcg) reportedly found improvements in alcohol misuse in 59% of treated participants versus 38% in control conditions. A contemporary open‑label pilot of psilocybin in AUD (N = 10; mean 15.1 years of dependence) with two psilocybin sessions plus Motivation Enhancement Therapy showed significant reductions in percent drinking days and heavy drinking days over 36 weeks compared with baseline. A larger double‑blind randomized trial of psilocybin for AUD is noted as ongoing (NCT02061293). Naturalistic survey data are also cited: in one survey of 343 respondents who used LSD or psilocybin, 83% reportedly no longer met AUD criteria after their psychedelic experience. Nicotine dependence: A single‑arm, open‑label study of psilocybin plus cognitive behavioural therapy for smoking cessation followed 15 treatment‑seeking smokers through a 15‑week protocol with two to three psilocybin sessions. Biochemical verification showed 12/15 (80%) abstinent at 6 months. Longer follow-up found 10/15 (67%) abstinent at 12 months and, in a subgroup with mean 30 months follow-up, 9/12 (60%) remained abstinent. Abstinent participants had significantly higher mystical‑experience scores. A larger randomized trial is underway (NCT01933994). Survey data (N = 358) similarly report substantial reductions or cessation after naturalistic psychedelic use. Opioids and stimulants: Early controlled work with LSD for opioid dependence (N = 78) is reported to have produced 25% biologically‑confirmed abstinence at 12 months in the LSD group versus 5% in controls, with brief relapses bringing the LSD‑group one‑year abstinence figure to 33% in some analyses. Contemporary pilot data for psilocybin in opioid use disorder (OUD) and a randomized trial in cocaine use disorder (initial N = 10/planned N = 40) are described as promising: preliminary results from the cocaine trial reportedly show significantly fewer days of use in the psilocybin arm versus diphenhydramine placebo, with effects maintained to 6‑month follow up. Large cross‑sectional analyses from national survey data (National Survey on Drug Use and Health) are cited: among ~44,000 respondents with illicit opioid use history, lifetime classic psychedelic use was associated with a 27% lower risk of past‑year opioid dependence and a 40% lower risk of past‑year opioid abuse. Religious and naturalistic contexts: Observational and anthropological evidence from religious traditions that use ayahuasca or peyote (DMT and mescaline respectively) is presented, with some studies reporting lower levels of SUD/AUD in populations regularly using these sacraments. An ayahuasca retreat study in Canada found reported reductions in alcohol, tobacco and cocaine use for participants. Survey work also reports reductions in cannabis, opioid and stimulant problems after naturalistic psychedelic experiences (e.g. one survey of N = 444 reported SUD criteria dropping from 96% pre‑experience to 27% post‑experience among respondents). Taken together, the authors present converging, though mostly preliminary, evidence across controlled trials, open‑label pilots, and observational studies that classic psychedelics may reduce substance use across multiple substance classes, and that the intensity of mystical‑type experiences correlates with better outcomes.

Yaden and colleagues interpret the assembled evidence as suggesting classic psychedelics could be a uniquely compatible adjunct to twelve‑step facilitation (TSF) programmes because both emphasise a spiritual or self‑transcendent turning point as central to recovery. They highlight Bill Wilson's historical use of hallucinogens and later advocacy for LSD as an often‑overlooked precedent for integration, arguing that psychedelic‑induced mystical experiences map onto AA/TSF aims such as connection to a 'higher power' and relief from self‑centredness. The authors acknowledge important barriers and caveats. They note that most contemporary TSF programmes historically reject medication‑assisted treatments on philosophical grounds and that integration may raise ethical and practical challenges related to incorporating spirituality into regulated medical practice. The paper stresses the importance of definitional flexibility in 'spirituality' — it can denote supernatural belief or more secular experiences of connection and meaning — and suggests that AA's long tradition of interpretive flexibility (for example, "God as we understood Him") could allow inclusive approaches compatible with a range of spiritual or non‑spiritual stances. Practical considerations and future research directions are proposed rather than firm clinical recommendations. The authors recommend empirical study of the intersection between psychedelic use and TSF membership (for example, quantitative surveys and qualitative interviews with groups such as Psychedelics in Recovery) to explore mechanisms, acceptability, and potential impact on meeting attendance and social support. They caution about potential stigma and social exclusion if TSF groups ostracise members who pursue psychedelic treatments, and they emphasise that ethical issues around spiritual content in clinical care must be navigated carefully. The authors stop short of endorsing immediate adoption of psychedelics within medical TSF practice, instead calling for further objective investigation to establish optimal multi‑treatment protocols and to clarify safety, efficacy and implementation considerations.

The paper concludes that, although controversial to some, a body of historical, clinical and observational evidence indicates Bill Wilson supported the therapeutic use of classic psychedelics and that these treatments appear largely compatible with AA/TSF philosophies. Given AA/TSF's global reach, the authors argue that combining psychedelic treatments with TSF approaches could have substantial scale‑level implications for harm reduction. They encourage further research to determine the most beneficial ways to combine these modalities.