Table 5.
Summary of studies using classic and atypical psychedelics in non-ceremonial and ceremonial settings for polydrug use and abuse
| Substance | Author(s) | Year | Addiction | Study characteristics | Drug and dose | Main findings |
|---|---|---|---|---|---|---|
| a. Classic psychedelics (psilocybin, LSD, mescaline) | Garcia-Romeu et al. [56] | 2020 | Cannabis use disorder | Retrospective cross-sectional online survey study | Psilocybin | Following the reference psychedelic experience |
| Opioid use disorder | 444 individuals (cannabis n = 166); opioid n = 123; stimulants n = 155) who met Drug Use Disorders Identification Test-Consumption (DUDIT-C) and DSM-V criteria for their primary drug/class of interest | LSD | 1. 28% reported less severe withdrawal symptoms, particularly craving compared to prior attempts (56% of cannabis users and 75% of opioid users) | |||
| Stimulant use disorder | Moderate to high doses | 2. 74.5% greatly reduced or quit using their primary substance (DUDIT-C) | ||||
| 3. Out of 95.7% substance use disorder (SUD) criteria before the reference psychedelic experience, only 27.3% met SUD criteria in the time since their reference psychedelic experience | ||||||
| Agin-Liebes et al. [57] and Uthaug et al. [58] (both utilising the same dataset) | 2021 | Alcohol use disorder | Retrospective naturalistic online survey | Mescaline (San Pedro) | 48% reported having the most memorable experience | |
| 2022 | Drug use disorder | 452 participants | Moderate to high dose (8–13 h) | Participants with previous substance misuse/dependence reported improvement following their most memorable experience | ||
| International epidemiological study | Oral self-administration for spiritual and nature connection | 1. Alcohol misuse/use disorder = 76% (n = 48) | ||||
| 2. Drug misuse/use disorder = 68% (n = 58) | ||||||
| 2–5% of participants with psychiatric conditions reported intentions to address/resolve their condition with mescaline | ||||||
| b. Atypical psychedelics (ibogaine, 5-MeO-DMT) | Schenberg et al. [60] | 2014 | Polydrug abuse | Retrospective observational study | Ibogaine | One treatment of ibogaine led to median of 5.5 months abstinence |
| Data from 75 polydrug (alcohol, cannabis, cocaine, crack cocaine) users (DSM-IV) | Single dose of Ibogaine HCl: 17 mg/kg | Multiple treatments of ibogaine led to median of 8.4 months abstinence | ||||
| Combined approach of ibogaine and cognitive behavioural therapy (clinic in Brazil) | If weak response to initial dose, they would increase up to 20 mg/kg | Both single and multiple ibogaine treatments led to statistically significant longer periods of abstinence than before the first ibogaine treatment | ||||
| Option for multiple treatment was available if individuals were experiencing intense craving, relapse, difficulty changing old drug-related habits | ||||||
| Davis et al. [61] | 2018 | Alcohol use disorder | Retrospective online survey study | 5-MeO-DMT | 66% reported improvement in AUD symptoms e.g., craving/desire | |
| Substance use disorder (non-alcohol) | 515 responders | Dose N/A | 60% reported improvement SUD symptoms e.g., craving/desire | |||
| Mash et al. [42] | 2018 | Opioid use disorder | Retrospective observational stud of 191 open-label case series | Ibogaine | Significant decrease in craving symptoms post-treatment and at 1-month follow-up | |
| Cocaine use disorder | Treatment (detoxification) seeking opioid and cocaine dependent (DSM-IV) individuals | Ibogaine HCl: 8–12 mg/kg | Significant decrease in depression symptoms at 1-month follow-up | |||
| Treatment program also included motivational counselling and referral to aftercare programs and community support groups | Decrease in withdrawal symptoms individually (no statistical significance) | |||||
| c. Ceremonial psychedelic use (DMT-containing ayahuasca brew) | Fábregas et al. [62] | 2010 | Polydrug abuse | 127 ritual jungle- and urban-based ayahuasca users and 115 rural controls (Brazil) | Ayahuasca | Ritual ayahuasca users relative to controls showed significantly |
| Addiction severity was assessed using the ASI | Dose N/A | 1. Lower ASI Alcohol scores | ||||
| 2. Lower scores in the Psychiatric Status subscales | ||||||
| 3. Lower drug use (except of cannabis) | ||||||
| Thomas et al. [63] (no access to full paper) | 2013 | Polydrug abuse | Observational prospective study | Ayahuasca | Self-reported alcohol, tobacco and cocaine use declined | |
| “Working with Addiction and Stress” retreat combined 4 days of group counselling with two expert-led ayahuasca ceremonies | Dose N/A | Statistically significant reductions in problematic cocaine use | ||||
| Twelve polydrug (alcohol, opioids, cocaine, tobacco, cannabis) rural aboriginal population users (Canada) | ||||||
| Barbosa et al. [64] | 2018 | Alcohol use disorder | Cross-sectional study with ayahuasca users and national normative sample (Brazil) | Ayahuasca | Alcohol and tobacco use disorder were lower in ritual ayahuasca using UVD members | |
| Tobacco use disorder | 1,947 Uniao do Vegetal (UDV) church members | Dose N/A | Reduction of alcohol and tobacco use disorder was significantly impacted by | |||
| Alcohol and tobacco use was evaluated through questionnaires first developed by World Health Organisation and the Substance Abuse and Mental Health Services Administration | 1. Attendance at ayahuasca ceremonies during the previous 12 months | |||||
| 2. Years of UDV membership |
ASI, Addiction Severity Index; AUD, alcohol use disorder; DSM, Diagnostic and Statistical Manual of Mental Disorders; DUDIT-C, Drug Use Disorders Identification Test-Consumption; UDV, Uniao do Vegetal (churches); 5-Meo-DMT, O-methyl-bufotenin.