Classic Psychedelics in Addiction Treatment: The Case for Psilocybin in Tobacco Smoking Cessation

Johnson frames tobacco smoking as a major global public‑health problem with very high mortality and limited long‑term success for existing behavioural and pharmacological cessation aids. The introduction defines "classic psychedelics" as drugs whose primary mechanism is agonism at the 5‑HT2A receptor (for example psilocybin, LSD, mescaline, and DMT) and situates renewed interest in these compounds as potential anti‑addiction medicines given historical reports and recent pilot data. The paper sets out to review multiple lines of evidence relevant to the hypothesis that classic psychedelics can facilitate recovery from substance use disorders, with a special focus on psilocybin for tobacco smoking cessation. Johnson outlines the plan to cover mid‑twentieth century clinical research, anthropological and epidemiological studies, modern clinical trials for alcohol and tobacco use disorders, and to highlight future research priorities and gaps.

The extracted text does not present a distinct Methods section or describe a formal systematic search strategy, inclusion/exclusion criteria, or risk‑of‑bias assessment. Instead, the paper is a narrative review that integrates historical clinical studies, anthropological reports, epidemiological analyses, contemporary pilot trials and survey research to build a case for psilocybin and other 5‑HT2A receptor agonists as candidate treatments for addictions.

Historical clinical literature from the 1950s–1970s is summarised as large in volume though heterogeneous and often not meeting modern methodological standards; more than 1,000 papers reported treatment of over 40,000 patients with 5‑HT2A agonists. Early work most commonly targeted alcoholism, frequently using LSD and, to a lesser extent, mescaline and other compounds. Although early trials often reported non‑significant positive trends, a later meta‑analysis of randomized LSD trials (six studies, total N=536) reported a significant and large reduction in alcohol misuse at the first follow‑up (about 1 month) for LSD versus control. A randomized trial of LSD for opioid dependence (N=78) under judicial supervision reported higher biologically confirmed abstinence in the LSD group, with continuous abstinence at 12 months of 25% versus 5% in controls, though that study had notable differences in residential treatment between arms. Anthropological sources are reported to link ritualised 5‑HT2A agonist use (for example peyote in the Native American Church and ayahuasca in Amazonian contexts) with reduced addictive substance use and long‑term abstinence in those cultural settings; the author notes the difficulty of disentangling drug effects from the broader religious and community context. Epidemiological analyses cited include a National Survey on Drug Use and Health analysis showing a lifetime history of 5‑HT2A agonist use was associated with a 27% reduced risk of past‑year opioid dependence among those who had ever used illicit opioids (sample described as N≈44,000 for that subgroup). Several online survey studies conducted or described by the Hopkins group are reported. An alcohol use disorder (AUD) survey (N=343) found respondents attributed reductions in alcohol use to prior 5‑HT2A agonist experiences after years of problematic drinking. A mixed‑substance survey (N=444) reported similar retrospective attributions for reductions in cannabis, opioid, or stimulant use. In these surveys, higher reported dose, greater personal meaning, and greater insight during the psychedelic experience were associated with larger self‑reported reductions in substance use. The author emphasises that these uncontrolled surveys cannot establish causality. Modern clinical work with psilocybin in AUD and tobacco use disorder is described in more detail. An open‑label AUD pilot (N=10) administered one or two psilocybin doses (0.3 and 0.4 mg/kg) alongside motivational enhancement therapy and reported substantial reductions in percentage of drinking days and percentage of heavy drinking days: mean drinking days in the 4 weeks prior to dosing were ~32.5% and reduced to ~12.5% in the 4 weeks following dosing and ~17.5% at a later follow‑up (21–32 weeks). Heavy drinking days decreased from ~26% to ~8% after dosing and ~13% at the later follow‑up. The Hopkins open‑label pilot for tobacco smoking cessation (N=15 treatment‑resistant smokers) combined a 15‑week manualised cognitive behavioural therapy programme with up to three psilocybin sessions (first session 20 mg/70 kg, later sessions typically 30 mg/70 kg). Participants averaged 51 years of age, had smoked for ~31 years and consumed ~19 cigarettes per day. Biologically verified 7‑day point‑prevalence abstinence was 80% (12/15) at 6 months, 67% at 12 months, and 60% at long‑term follow‑up (mean ≈2.5 years; follow‑up range 16–57 months). Continuous abstinence was 53% at 12 months and 47% at the long‑term follow‑up. Nine of 15 participants (60%) met criteria for a "complete" mystical‑type experience on at least one session; higher mystical‑experience scores were associated with 6‑month abstinence and greater reductions in cigarette craving. Structured qualitative interviews conducted at mean 2.5 years post‑quit highlighted themes of changed self‑identity, increased interconnectedness, awe and curiosity, and secondary psychosocial benefits such as increased prosocial behaviour. Additional survey work by the Hopkins group (N=781 respondents regarding psychedelic‑related smoking reductions, 358 with the psychedelic experience >1 year prior) reported that participants judged withdrawal‑related negative affect to be much less severe after their psychedelic experiences compared to prior quit attempts. The author notes ongoing randomised trials, including a head‑to‑head study comparing a single psilocybin session to transdermal nicotine patch with CBT in both arms, and other registered trials for cocaine and opioid use disorders. Across the evidence, the author emphasises two recurring observations: (1) substantial preliminary signals of efficacy across multiple substances and study types, and (2) a consistent association between the qualitative intensity or personal meaning of the psychedelic session (often operationalised as a mystical‑type experience) and longer‑term positive behavioural outcomes. The paper also notes harms associated with uncontrolled psychedelic use and stresses that clinical protocols include screening, preparation, session monitoring and aftercare to reduce risks.

Johnson interprets the assembled evidence as suggestive that classic psychedelics, and psilocybin in particular, hold promise as treatments for substance use disorders including tobacco and alcohol use disorders. He argues that convergent signals—from historical clinical studies, anthropological reports, epidemiological associations, uncontrolled surveys, small modern pilots, and a meta‑analysis of older LSD trials—support further rigorous investigation. A central explanatory hypothesis advanced is that psychedelics may produce persisting positive behaviour change not by a drug‑specific pharmacological blockade of a particular addictive agent, but by amplifying psychotherapeutic processes such as meaning‑making, corrective emotional experiences, and shifts in self‑narrative. The intensity and personal significance of the acute subjective experience (for example mystical‑type experiences) are posited as mediators or facilitators of the therapeutic change observed. The author explicitly acknowledges limitations and uncertainties: much of the historical and anthropological literature is uncontrolled; survey and epidemiological data cannot establish causality; and modern clinical evidence is dominated by small open‑label trials that may be susceptible to expectancy and selection biases. He notes specific methodological limitations in older trials (for example unequal residential treatment exposure in the LSD opioid study) and cautions that uncontrolled psychedelic use carries demonstrable harms. At the same time, Johnson points out that contemporary trials have followed safety guidelines (screening, preparation, monitoring, follow‑up) and that two decades of modern research indicate such trials can be conducted with an acceptable level of safety when protocols are followed. For clinical and research implications, the paper recommends larger, double‑blind randomised trials, dose‑finding studies, experimental manipulation of psychotherapeutic "set and setting" variables, and Phase III programmes if efficacy signals persist. Additional priorities noted include testing psychedelics across a broader range of substance use disorders (opioids, cocaine, methamphetamine, cannabis), examining other classic psychedelics (LSD, DMT, 5‑MeO‑DMT), evaluating shorter‑versus longer‑acting compounds for scalability, and researching optimal psychotherapeutic backdrops (for example CBT versus motivational enhancement versus minimal structured therapy). Johnson also calls for public funding to support multi‑site trials and highlights ongoing funded efforts and registered trials as steps in that direction.