Psilocybin & Addiction
83% reduction
Two psilocybin sessions reduced heavy drinking days by 83% compared to 51% in the placebo group, in a 93-person double-blind randomized trial published in JAMA Psychiatry.
Bogenschutz et al., JAMA Psychiatry, 2022
48% vs 24%
complete abstinence at 8 months: psilocybin vs placebo (Bogenschutz et al., 2022)
6 studies
cited in this guide including 2 from 2025
5 cluster
articles covering mechanisms, long-term data, and treatment comparisons
Bogenschutz et al., JAMA Psychiatry, 2022
View as image ↗In 2022, Bogenschutz and colleagues published results from the first large double-blind RCT of psilocybin for alcohol use disorder in JAMA Psychiatry. Two psilocybin sessions, combined with psychotherapy, reduced heavy drinking days by 83% compared to 51% in the placebo group. By the 8-month follow-up, 48% of participants who received psilocybin had stopped drinking entirely, compared to 24% in the placebo group.[1]
That is the short answer to whether psilocybin works for alcohol addiction. The longer answer requires understanding the trial design, where the 2025 data fits, and what a 2025 null result from a Swiss trial means for the field.
Key Takeaways
- The Bogenschutz 2022 JAMA Psychiatry RCT (n=93) found two psilocybin sessions with psychotherapy reduced heavy drinking days by 83% vs 51% in the placebo group, and achieved 48% complete abstinence vs 24% at 8-month follow-up
- A 2025 Swiss phase 2 RCT (Rieser et al., n=37) found no significant difference between single-dose psilocybin and placebo on the primary abstinence outcome — the key methodological difference is one session vs two sessions, not a contradiction of the NYU data
- A 2025 feasibility RCT (Luquiens et al., n=30) in patients with AUD and comorbid depression found preliminary efficacy signals and confirmed the protocol is feasible in a comorbid population
- Two systematic reviews (Goel 2022; van der Meer 2023) confirm consistent benefit signals for psilocybin across alcohol and tobacco use disorders, attributed to shared serotonergic mechanisms
- Psilocybin is not FDA-approved for AUD; it remains Schedule I in the US; clinical access currently requires enrollment in a research trial
- The Bogenschutz 2015 open-label proof-of-concept (n=10) established the 36-week durability of effects that justified the full RCT
The NYU Trial in Numbers: What Bogenschutz's 2022 RCT Actually Found
The primary question in the Bogenschutz 2022 trial was straightforward: do psilocybin sessions change drinking behavior compared to a credible placebo, in a controlled double-blind design?
The trial enrolled 93 adults with alcohol use disorder. Participants were randomized to receive either psilocybin (25mg or 30mg in two sessions) or diphenhydramine (an antihistamine used as an active placebo that produces mild psychoactive effects without psilocybin's action). Both groups received the same psychotherapy. The entire treatment and follow-up period ran for 32 weeks.[1]
The primary outcome was percentage of heavy drinking days during weeks 5 through 36. A heavy drinking day was defined as five or more drinks for men, four or more for women.
The results:
The psilocybin group reduced their heavy drinking days by 83% relative to baseline. The placebo group reduced by 51%. The difference was statistically significant and clinically large. Both groups showed improvement, which is typical in addiction trials with intensive psychotherapy — the comparison was never psilocybin vs. nothing.
At the 8-month follow-up, 48% of psilocybin participants had stopped drinking entirely. The placebo rate was 24%. Among people who were still drinking, those who had received psilocybin were drinking substantially fewer drinks per day.
The snippet answer to "what was the NYU psilocybin alcohol study": the Bogenschutz 2022 JAMA Psychiatry RCT (NYU Grossman School of Medicine and University of New Mexico) found that two psilocybin sessions with psychotherapy reduced heavy drinking days by 83% vs 51% in the placebo group, and achieved 48% complete abstinence vs 24% at 8 months, in a 93-person double-blind randomized trial.
For data on how long these effects lasted and how later studies replicate or diverge from these findings, see Psilocybin and Alcohol Use Disorder: Sustained Abstinence Data.
How the Trial Was Designed (What "Double-Blind" Means Here)
Blinding in psychedelic trials is genuinely difficult. Psilocybin produces an unmistakable subjective experience. Participants almost always know whether they received the active drug.
The Bogenschutz 2022 trial used diphenhydramine as the comparator specifically to address this. Diphenhydramine produces sedation and mild perceptual changes without psilocybin's primary psychedelic effects. It gives participants something to attribute their experiences to, and it maintains consistency in the psychotherapy sessions. Researchers and raters who assessed outcomes also did not know which drug participants received.[1]
Double-blind is a loose term in this context. A 2022 trial measuring outcomes based on self-report of drinking, with a drug that creates its own detectable experience, cannot achieve the same blinding as a trial of a pharmacologically inert sugar pill. The trial was designed to minimize this limitation as much as current methodology allows.
The two psilocybin sessions were conducted approximately four weeks apart. Between sessions and after sessions, participants received manualized psychotherapy focused on their relationship with alcohol. The psychotherapy was not a background element; it was considered an essential part of the protocol, not a control condition.
This matters for interpreting the results and for thinking about how psilocybin might eventually be used outside of research settings. The active ingredient is not the drug alone.
Before the JAMA Study: The 2015 Proof-of-Concept
Bogenschutz and colleagues published an earlier open-label pilot in 2015. That study enrolled 10 participants with alcohol dependence and administered psilocybin in two sessions alongside motivational enhancement therapy.[2]
With n=10 and no control condition, the 2015 study couldn't establish efficacy. What it established was safety and durability. Drinking decreased significantly after each psilocybin session. The gains held through the 36-week follow-up period — longer than most proof-of-concept addiction studies track outcomes.[2]
That 36-week durability finding gave investigators the justification to run the full RCT. When a proof-of-concept shows gains maintained at 9 months, the hypothesis is worth testing at scale.
Two 2025 Trials: Progress and a Null Result Worth Understanding
Two new trials published in 2025 add to the evidence base and complicate the story in important ways.
Rieser et al., 2025 (eClinicalMedicine, Lancet)
A Swiss team ran a phase 2 RCT with 37 participants. The protocol used a single 25mg psilocybin dose with five psychotherapy sessions. The primary outcome was abstinence duration, assessed at four weeks and six months.
The result: no significant difference between psilocybin and placebo on the primary outcome at either time point. Secondary outcomes showed some positive trends, but the main efficacy question was not answered positively.[3]
This is a genuine null result from a randomized trial. It cannot be dismissed. At the same time, the methodological difference from the Bogenschutz 2022 study is substantial and specific: one session versus two sessions. Whether a single psilocybin session produces the same clinical trajectory as two sessions spaced four weeks apart is a real question, and this trial suggests the answer may be no.
Luquiens et al., 2025 (Addiction)
A feasibility RCT enrolled 30 participants with alcohol use disorder and comorbid depression, a population often excluded from trials due to complexity. Participants received 25mg psilocybin (n=20) or a 1mg active placebo (n=10), plus psychotherapy. The primary objective was feasibility: can this population be recruited and retained? The secondary objective was preliminary efficacy.[4]
The feasibility question was answered yes — 350 people were screened to enroll 30, and retention was adequate. Preliminary efficacy signals were noted. This matters because comorbid depression and AUD is a common clinical reality, and a trial that excludes this population produces evidence that may not generalize to the patients most likely to seek treatment.
Why the Null Result Doesn't Contradict the NYU Data
The Rieser 2025 null result and the Bogenschutz 2022 positive result are consistent with a simple interpretation: one session may not be sufficient to produce the sustained outcomes that two sessions achieve.
This is not a retroactive rationalization. The single-session vs. two-session distinction was a specific design choice in both trials. Bogenschutz 2022 used two sessions spaced four weeks apart, with the second session building on insights from the first. Rieser 2025 used one session with follow-up psychotherapy only.
If two sessions at the right spacing and dose are necessary for durable abstinence, then a single-dose trial testing a different protocol isn't testing the same thing. The trials aren't contradicting each other; they're asking slightly different questions.
The honest caveat is that this explanation is post-hoc. The field needs a direct within-study comparison of one vs. two sessions, with the same population and psychotherapy protocol, to test this hypothesis properly. That trial hasn't been done yet.
For a detailed analysis of how the trial designs explain the outcome differences, see Psilocybin and Alcohol Use Disorder: Sustained Abstinence Data.
What the Systematic Reviews Say About Where Alcohol Fits
Beyond the individual trials, two systematic reviews provide context on psilocybin's therapeutic evidence base.
Goel and colleagues published a systematic review in Biomedicine and Pharmacotherapy in 2022, synthesizing psilocybin evidence across depression, anxiety, addiction, and PTSD. Across addiction applications, they found consistent benefit signals with a reasonable safety profile, while noting that most trials used small samples and that standardization of psychotherapy protocols varied.[5]
Van der Meer and colleagues published a systematic review specifically on psilocybin for addiction in Frontiers in Psychiatry in 2023. They reviewed evidence across tobacco, alcohol, and cocaine use disorders. Consistent benefit signals emerged for alcohol and tobacco. The proposed shared mechanism is serotonergic: psilocybin's 5-HT2A receptor activity appears to act on circuits involved in reward, craving, and habitual behavior across different substance use disorders.[6]
The parallel evidence from tobacco is relevant context. A separate Johns Hopkins study achieved an 80% tobacco quit rate with psilocybin sessions, one of the highest quit rates recorded for any pharmacological or behavioral intervention. The fact that psilocybin produces comparable signals across distinct addictions suggests the mechanism is substrate-general rather than specific to alcohol. For the smoking cessation data, see 80% Quit Rate: How Psilocybin Helps Smokers Stop.
How Psilocybin Produces These Effects: A Mechanism Overview
The clinical results raise a mechanistic question: what does psilocybin actually do that produces lasting changes in drinking behavior after only two sessions?
The full mechanistic story involves 5-HT2A receptor activation, changes in craving-related circuits in the brain's reward center, normalization of a molecular pathway involved in both cognitive impairment and craving in alcoholism, and disruption of the default mode network — a brain circuit involved in self-referential thought and habitual mental patterns. The mechanism is covered in depth, including the 2024 data on nucleus accumbens specificity and the 2021 rat study that identified the molecular craving circuit psilocybin targets, at How Psilocybin Helps People Stop Drinking: Mechanisms.
One mechanistic finding worth noting here: a 2023 preclinical study found that alcohol dependence itself blunts psilocybin's normal effects on the default mode network. In alcohol-dependent animals, psilocybin's typical circuit-disruption effect was reduced compared to non-dependent animals. If this finding translates to humans, it suggests that more severely dependent patients may need higher doses or more sessions to achieve the same neural effects. This provides another possible mechanistic explanation for why single-session protocols produce weaker outcomes in heavily dependent populations.
For context on the broader role of mystical experience as a proposed psychological mediator of psilocybin's addiction effects, see The Mystical Experience and Addiction Recovery: Why It Matters.
The Trial Data at a Glance
| Trial | Year | n | Design | Key Outcome |
|---|---|---|---|---|
| Bogenschutz et al. | 2015 | 10 | Open-label pilot | Gains maintained at 36 weeks |
| Bogenschutz et al. | 2022 | 93 | Double-blind RCT, 2 sessions | 83% vs 51% heavy drinking reduction; 48% vs 24% abstinence |
| Rieser et al. | 2025 | 37 | Phase 2 RCT, 1 session | No significant primary outcome vs placebo |
| Luquiens et al. | 2025 | 30 | Feasibility RCT, AUD+depression | Protocol feasible; preliminary efficacy signal |
The pattern across this table is consistent with the single-session vs. two-session hypothesis: the only null result comes from a single-session protocol.
What the Current Evidence Means for Access
Psilocybin is classified as a Schedule I controlled substance in the United States, meaning it has no currently accepted medical use and no legal route to clinical access outside of research trials. The FDA granted psilocybin Breakthrough Therapy Designation for major depression in 2018 and for treatment-resistant depression in 2019, but no Breakthrough Therapy Designation exists specifically for AUD. FDA approval for any psilocybin indication requires additional Phase 3 trial data.
For context on how psilocybin compares to currently approved alcohol use disorder medications like naltrexone and acamprosate, see Psilocybin vs. Naltrexone for Alcohol Addiction: How They Compare.
For a single psilocybin session's effects on drinking behavior, including the Jensen 2025 data and the Pagni 2024 brain imaging data, see One Psilocybin Session and Reduced Drinking: The Research.
The Bottom Line
The Bogenschutz 2022 JAMA Psychiatry RCT remains the strongest evidence for psilocybin in alcohol use disorder: two sessions reduced heavy drinking days by 83% vs 51% in a 93-person double-blind trial, with 48% complete abstinence at 8 months. The 2025 trial landscape adds nuance rather than contradiction: the only null result came from a single-session protocol, consistent with the possibility that two sessions are necessary for durable outcomes. Two systematic reviews confirm consistent benefit signals across psilocybin addiction applications. Psilocybin remains investigational and Schedule I in the US, with no clinical access pathway outside research enrollment.
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