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Arnt Schellekens

Department of Psychiatry, Radboud University Medical Center, Nijmegen, The Netherlands.

7 papers in the library · 274 citations · publishing 2016-2026

Papers

Therapeutic effect of psilocybin in addiction: A systematic review

Frontiers in Psychiatry February 9, 2023 Kees Kramers, Arnt Schellekens, Metten Somers et al. 119 citations

A systematic review of psilocybin-assisted therapy for substance use disorders identified four clinical trials (six articles) involving 151 patients, with doses from 6 to 40 mg. Three studies focused on alcohol use disorder and one on tobacco use disorder. In a pilot study (n=10), heavy drinking days decreased significantly. In another single-arm study (n=31), 32% achieved complete alcohol abstinence over an average of 6 years. A double-blind, placebo-controlled RCT (n=95) found significantly fewer heavy drinking days with psilocybin versus placebo. In a pilot study (n=15), smoking abstinence at 26 weeks was 80% and at 52 weeks 67%. All trials indicated beneficial effects, but larger RCTs are needed.

Psilocybin for treating substance use disorders?

Expert Review of Neurotherapeutics August 10, 2016 Bas T.h. de Veen, Arnt Schellekens, Michel M. M. Verheij et al. 102 citations

Existing treatments for substance use disorders (SUD) are only partially effective. Psilocybin, a hallucinogen with a chemical structure similar to serotonin, may offer a new treatment option. Psilocybin administration spikes cortisol levels and activates the executive control network, increasing control over emotional processes and relieving negative thinking and persistent negative emotions. Preliminary data from ongoing human studies on alcohol and smoking addiction show promising effects on substance use. Psilocybin has low risk of toxicity and dependence and can be used safely under controlled conditions. Recent positive findings need confirmation in well-designed placebo-controlled randomized trials with large sample sizes.

Safety of ibogaine administration in detoxification of opioid-dependent individuals: a descriptive open-label observational study.

Addiction (Abingdon, England) January 1, 2022 Thomas Knuijver, Arnt Schellekens, Maarten Belgers et al. 49 citations

A single dose of ibogaine (10 mg/kg) in 14 patients with opioid use disorder caused an average QTc prolongation of 95 ms (range 29–146 ms); half of the subjects reached a QTc over 500 ms. No life-threatening cardiac events occurred, but severe temporary ataxia (inability to walk without support) was universal. Withdrawal and psychomimetic effects were mostly manageable; 11 of 14 patients did not return to morphine within 24 hours. The findings indicate that ibogaine induces clinically relevant but reversible QTc prolongation, bradycardia, and severe cerebellar toxicity.

Psychedelic Research for Alcohol Use Disorder with Comorbid Major Depressive Disorder: An Unmet Need.

Current psychiatry reports December 1, 2024 Daan de Jonge, Pim B van der Meer, Cornelis Kramers et al. 2 citations

A narrative review of psilocybin- and LSD-assisted treatment for alcohol use disorder (AUD) and major depressive disorder (MDD) finds growing evidence that psilocybin produces a sustained reduction in drinking frequency among people with AUD, and a recent meta-analysis shows psilocybin therapy yields a large and consistent decrease in depressive symptoms compared to no treatment. AUD and MDD frequently co-occur, and this comorbidity worsens symptoms of both disorders and complicates treatment. The authors argue that an integrated therapy addressing both conditions simultaneously could benefit such patients and call for more research on psilocybin in this dual-diagnosis population.

Ibogaine is associated with reorganization of high-beta brain networks in veterans with post-traumatic stress disorder

bioRxiv (Cold Spring Harbor Laboratory) March 24, 2026 Kenneth Shinozuka, Mattia Rosso, Anna Chaiken et al. 1 citation

A single dose of the atypical psychedelic ibogaine can be highly effective at treating PTSD in veterans up to twelve months later, according to an observational study of 30 veterans. Using a novel EEG analysis method, researchers found that ibogaine shifted high-beta (24 and 25 Hz) brain networks from frontal areas toward posterior regions, an effect seen both three to four days and one month after treatment. This posterior shift correlated with improvements in PTSD symptoms and was replicated in an independent dataset on ibogaine for opioid use disorder. Neural modeling suggested the shift reflects increased corticocortical, not corticothalamic, connectivity. The reconfiguration of high-beta networks may be a robust biomarker for ibogaine's therapeutic effects.

Treatment of heroin dependence with ibogaine

European Psychiatry March 1, 2016 Arnt Schellekens, Toon van Oosteren, Thomas Knuijver et al. 1 citation

Ibogaine, a hallucinogen, reduces drug self-administration in animals, especially within the first 24 hours, but causes motor impairment and cerebral cell loss. In a meta-analysis of 27 animal studies, ibogaine did not affect conditioned place preference. Human data from 15 opiate-dependent patients treated with 10 mg/kg ibogaine are still being collected; initial observations show strong QTc prolongation and ataxia, with relatively mild opiate withdrawal symptoms. Ibogaine may reduce opiate withdrawal but carries risks of transient cardiac and cerebellar toxicity, warranting further systematic studies on its safety and efficacy for treating opiate dependence.

Efficacy and Safety of Psychoactive Tryptamines in Addiction: A Systematic Review

Psychedelic Medicine October 8, 2025 Pim B. van der Meer, Nout Schukking, Miranda G. Dik et al.

A systematic review of clinical trials found limited evidence that psychoactive tryptamines other than psilocybin and ibogaine are effective for treating substance use disorders. Four trials involving 176 patients with alcohol use disorder tested dipropyltryptamine and diethyltryptamine. Abstinence rates ranged from 10% to 38% at 26 weeks of follow-up, and severity of alcohol use did not differ between the tryptamine and control groups. Adverse effects were poorly reported. The review concludes that studies are scarce and show limited evidence for effectiveness in treating addictive disorders.