OPEN Foundation

Substance Use Disorder

Neural Mechanisms Underlying the Rewarding and Therapeutic Effects of Ketamine as a Treatment for Alcohol Use Disorder

Abstract

Alcohol use disorder (AUD) is the most prevalent substance use disorder and causes a significant global burden. Relapse rates remain incredibly high after decades of attempting to develop novel treatment options that have failed to produce increased rates of sobriety. Ketamine has emerged as a potential treatment for AUD following its success as a therapeutic agent for depression, demonstrated by several preclinical studies showing that acute administration reduced alcohol intake in rodents. As such, ketamine’s therapeutic effects for AUD are now being investigated in clinical trials with the hope of it being efficacious in prolonging sobriety from alcohol in humans (ClinicalTrials.gov, Identifier: NCT01558063). Importantly, ketamine’s antidepressant effects only last for about 1-week and because AUD is a lifelong disorder, repeated treatment regimens would be necessary to maintain sobriety. This raises questions regarding its safety for AUD treatment since ketamine itself has the potential for addiction. Therefore, this review aims to summarize the neuroadaptations related to alcohol’s addictive properties as well as ketamine’s therapeutic and addictive properties. To do this, the focus will be on reward-related brain regions such as the nucleus accumbens (NAc), dorsal striatum, prefrontal cortex (PFC), hippocampus, and ventral tegmental area (VTA) to understand how acute vs. chronic exposure will alter reward signaling over time. Additionally, evidence from these studies will be summarized in both male and female subjects. Accordingly, this review aims to address the safety of repeated ketamine infusions for the treatment of AUD. Although more work about the safety of ketamine to treat AUD is warranted, we hope this review sheds light on some answers about the safety of repeated ketamine infusions.

Strong, C. E., & Kabbaj, M. (2020). Neural Mechanisms Underlying the Rewarding and Therapeutic Effects of Ketamine as a Treatment for Alcohol Use Disorder. Frontiers in behavioral neuroscience, 14, 593860. https://doi.org/10.3389/fnbeh.2020.593860

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A non-hallucinogenic psychedelic analogue with therapeutic potential

Abstract

The psychedelic alkaloid ibogaine has anti-addictive properties in both humans and animals1. Unlike most medications for the treatment of substance use disorders, anecdotal reports suggest that ibogaine has the potential to treat addiction to various substances, including opiates, alcohol and psychostimulants. The effects of ibogaine-like those of other psychedelic compounds-are long-lasting2, which has been attributed to its ability to modify addiction-related neural circuitry through the activation of neurotrophic factor signalling3,4. However, several safety concerns have hindered the clinical development of ibogaine, including its toxicity, hallucinogenic potential and tendency to induce cardiac arrhythmias. Here we apply the principles of function-oriented synthesis to identify the key structural elements of the potential therapeutic pharmacophore of ibogaine, and we use this information to engineer tabernanthalog-a water-soluble, non-hallucinogenic, non-toxic analogue of ibogaine that can be prepared in a single step. In rodents, tabernanthalog was found to promote structural neural plasticity, reduce alcohol- and heroin-seeking behaviour, and produce antidepressant-like effects. This work demonstrates that, through careful chemical design, it is possible to modify a psychedelic compound to produce a safer, non-hallucinogenic variant that has therapeutic potential.

Cameron, L. P., Tombari, R. J., Lu, J., Pell, A. J., Hurley, Z. Q., Ehinger, Y., Vargas, M. V., McCarroll, M. N., Taylor, J. C., Myers-Turnbull, D., Liu, T., Yaghoobi, B., Laskowski, L. J., Anderson, E. I., Zhang, G., Viswanathan, J., Brown, B. M., Tjia, M., Dunlap, L. E., Rabow, Z. T., … Olson, D. E. (2021). A non-hallucinogenic psychedelic analogue with therapeutic potential. Nature, 589(7842), 474–479. https://doi.org/10.1038/s41586-020-3008-z

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Therapeutic effects of classic serotonergic psychedelics: A systematic review of modern-era clinical studies

Abstract

Objective: To conduct a systematic review of modern-era (post-millennium) clinical studies assessing the therapeutic effects of serotonergic psychedelics drugs for mental health conditions. Although the main focus was on efficacy and safety, study characteristics, duration of antidepressants effects across studies, and the role of the subjective drug experiences were also reviewed and presented.

Method: A systematic literature search (1 Jan 2000 to 1 May 2020) was conducted in PubMed and PsychINFO for studies of patients undergoing treatment with a serotonergic psychedelic.

Results: Data from 16 papers, representing 10 independent psychedelic-assisted therapy trials (psilocybin = 7, ayahuasca = 2, LSD = 1), were extracted, presented in figures and tables, and narratively synthesized and discussed. Across these studies, a total of 188 patients suffering either cancer- or illness-related anxiety and depression disorders (C/I-RADD), major depressive disorder (MDD), obsessive-compulsive disorder (OCD) or substance use disorder (SUD) were included. The reviewed studies established feasibility and evidence of safety, alongside promising early data of efficacy in the treatment of depression, anxiety, OCD, and tobacco and alcohol use disorders. For a majority of patients, the therapeutic effects appeared to be long-lasting (weeks-months) after only 1 to 3 treatment session(s). All studies were conducted in line with guidelines for the safe conduct of psychedelic therapy, and no severe adverse events were reported.

Conclusion: The resurrection of clinical psychedelic research provides early evidence for treatment efficacy and safety for a range of psychiatric conditions, and constitutes an exciting new treatment avenue in a health area with major unmet needs.

Andersen, K., Carhart-Harris, R., Nutt, D. J., & Erritzoe, D. (2021). Therapeutic effects of classic serotonergic psychedelics: A systematic review of modern-era clinical studies. Acta psychiatrica Scandinavica, 143(2), 101–118. https://doi.org/10.1111/acps.13249

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Combining Ketamine, Brain Stimulation (rTMS) and Mindfulness Therapy (TIMBER) for Opioid Addiction

Abstract

Opioid addiction in the United States currently presents a national crisis despite availability of different treatments. Prior findings suggest that both repetitive transcranial magnetic stimulation (rTMS) and subanesthetic dose of ketamine are efficacious in patients with opioid use disorders (OUD) when administered in isolation. However, their therapeutic value may be undermined by varying clinical responses that tend to dissipate with treatment cessation. There has been no study to date that has used a combination of both for OUD, and there are still many unanswered questions with respect to both. TIMBER (Trauma Interventions using Mindfulness Based Extinction and Reconsolidation of memories) therapy attempts to alter the expression of emotionally charged memories such as traumatic memories, and has been successfully tried in chronic post-traumatic stress disorder (PTSD) and in combination with memory-altering pharmacotherapy like ketamine infusion. By a combination of extinction and reconsolidation of memory approaches, TIMBER works to not over-flood and/or retraumatize as is seen in other treatment approaches. TIMBER involves a balanced combination of both the memory extinction and memory reconsolidation approaches (rather than extinction-only approaches) which explains its superior efficacy in PTSD and benefit in substance use disorders.

Pradhan, B., & Rossi, G. (2020). Combining Ketamine, Brain Stimulation (rTMS) and Mindfulness Therapy (TIMBER) for Opioid Addiction. Cureus, 12(11), e11798. https://doi.org/10.7759/cureus.11798

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Psychedelics as an emerging novel intervention in the treatment of substance use disorder: a review

Abstract

Classical psychedelics are a group of drugs characterized by their activation of the serotonin-2A (5-hydroxytryptamine-2A; 5-HT2A) receptor and the unique hallucinogenic and mystical-type experiences that result. After a substantial period of restrictions limiting investigations into the therapeutic potential of psychedelics, a relatively recent recommencement of interest has sparked the burgeoning possibility for these drugs to play a part in the treatment of a wide array of psychopathologies. One of the most promising is in the study of addiction. Evidence has emerged that psychedelic agents may provide a novel avenue for the clinical treatment of patients dealing with substance use disorders (SUD). These serotonergic hallucinogens have displayed remarkable and enduring positive outcomes in this area, even when administered as one or two doses. The neural targets for these psychedelics are varied and underlie a complex mechanism of action-modulating multiple neural networks. It is believed that these agents allow for the reorganization of disordered neural pathways in the default mode network and attenuate maladaptive signaling in mesolimbic reward circuitry. The aim of this review is to examine the current standing of evidence regarding psychedelic psychopharmacology and to provide an overview of the use and effectiveness of these drugs in the treatment of SUD, alcohol use disorder, and for smoking cessation.

DiVito, A. J., & Leger, R. F. (2020). Psychedelics as an emerging novel intervention in the treatment of substance use disorder: a review. Molecular biology reports, 47(12), 9791–9799. https://doi.org/10.1007/s11033-020-06009-x

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Treating drug addiction with psychedelics looks promising

Although controversial only a few years ago, there is ample evidence that psychedelics can help in the fight against addictions (use disorders). Over the past decades, there have been multiple studies looking into the workings of psychedelics in the field of addiction. Multiple trials have concluded that there are indeed possibilities to develop psychedelic-assisted treatments towards treating multiple drug addictions. Below we list just a few promising areas which include LSD for alcoholism, psilocybin for smoking cessation and alcoholism, and ibogaine for opioid addiction.
Back at ICPR2012, researchers from Norway presented a meta-analysis of randomized controlled trials using lysergic acid diethylamide (LSD) for alcoholism. Researchers Krebs and Johansen had found six trials done in the 1960s and 1970s that included a total of 536 participants. The researchers concluded that “A single dose of LSD, in the context of various alcoholism treatment programs, is associated with a decrease in alcohol misuse.” The results of the meta-analysis were published in the Journal of Psychopharmacology that same year and made it to mainstream media.
Contemporary addiction research has focused on using two compounds in particular: psilocybin and ibogaine. LSD is less researched, perhaps because of stigma or the long active duration of the psychedelic effects of LSD. Ketamine and MDMA are also researched and covered in this year’s online conference. Preliminary studies suggest that these compounds may help with the treatment of drug-related disorders. However, it is still not completely clear how their mechanism of action results in the observed outcomes.
At Johns Hopkins School of Medicine, Professor Matthew Johnson conducted a study with psilocybin and tobacco smokers. Twelve of the 15 participants managed to quit tobacco smoking, and importantly: maintained their decision to quit. Although it was a small sample group, a success rate of 80% was enough to warrant studies with larger groups.

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Johnson, who is currently the President-Elect of the International Society for Research on Psychedelics, will give a talk at our Psychedelics in Psychiatry and Psychotherapy Symposium on the working mechanisms of psychedelics used in clinical research.

What could be the mechanism of action that helps people kick their addiction when treated with psychedelics? I an interview we did with Prof. Johnson in 2015 he stated that: “evidence suggests that there are psychological mechanisms of action at play. For example, people endorse that after the psilocybin sessions, it was easier for them to make decisions that were in their long-term best interest, and they were less likely to make decisions based on short-term, hedonistic desires.” They also seemed to feel more in control of decisions about their behavior, and Johnson says “they also reported an increase in their self-efficacy, their confidence in their ability to remain quit.”
Another area where psilocybin seems promising is in treating alcoholism. Addiction researcher Michael Bogenschutz at New York University has been interested in alcohol-related treatments and is now conducting studies using psilocybin: “I’m interested in addiction in general but for me alcohol, which is a very common, devastating addiction throughout the world, was a logical place to start. As I learned when I started investigating the topic, a considerable amount of research on the use of psychedelic treatment (mainly LSD) and alcohol had already been conducted in the late 1950s.”

Elizabeth M. Nielson, PhD, CASAC - Psychedelic.Support
At ICPR2020 Dr. Elisabeth Nielson will present the historical context and current clinical research on Psilocybin-Assisted Treatment of Alcohol Use Disorder.
In addition, at the upcoming International Symposium on Psychedelics in Psychiatry and Psychotherapy (ISPPP) there are several presentations about clinical application for psychedelics in alcoholism, including the Bristol Imperial MDMA in Alcoholism Study (BIMA) which is an open label within-subject feasibility study in 20 patients with Alcohol Use Disorder who have recently undergone detoxification. The study is conducted by Ben Sessa, MD, one of the ICPR2020 speakers, and its principal investigator is Professor David Nutt.

A less known psychedelic compared to psilocybin and MDMA is ibogaine, which is derived from the African plant Tabernanthe iboga. Ibogaine was a hot topic at this year’s World Economic Forum which included positive reports on ibogaine’s potential role as an addiction interrupter for opioid addiction.
In the Netherlands, researchers at the Radboud University have been investigating the use of ibogaine for addiction. During ICPR2016, researchers from Radboud shared some promising pre-clinical evidence for the efficacy of ibogaine in treating addiction and shared some of the challenges of conducting psychedelic research in the Netherlands.
Currently there are several clinical research projects recruiting participants for psychedelic research in the Netherlands and Europe.
Luís Fernando Tófoli, who is a Professor of Psychiatry at the Faculty of Medical Sciences of the University of Campinas, Brazil, gave a fascinating review at ICPR2016 about brain imaging studies on psychedelics and their relation to addiction studies. Reviewed results point to effects in the medial prefrontal cortex, the anterior and posterior cingulate cortex and the precuneus. Psychedelics also seem to affect limbic structures (e.g. amygdala), insula, occipital lobe and, less frequently, thalamus and they have been associated with a deactivation of the default mode network. Psychedelics have a relatively modest impact on dopaminergic circuits associated with addiction, but they affect structures implicated in cue processing and decision-making in drug-seeking behavior.
At ICPR2020, Prof. Tófoli is returning, this time discussing the role of integration in psychedelic experiences, including in the treatment of addiction with ibogaine in biomedical clinics.

Psychedelic science in post-COVID-19 psychiatry

Abstract

The medium- to long-term consequences of COVID-19 are not yet known, though an increase in mental health problems are predicted. Multidisciplinary strategies across socio-economic and psychological levels may be needed to mitigate the mental health burden of COVID-19. Preliminary evidence from the rapidly progressing field of psychedelic science shows that psilocybin therapy offers a promising transdiagnostic treatment strategy for a range of disorders with restricted and maladaptive habitual patterns of cognition and behaviour, notably depression, addiction and obsessive compulsive disorder. The COMPASS Pathways (COMPASS) phase 2b double-blind trial of psilocybin therapy in antidepressant-free, treatment-resistant depression (TRD) is underway to determine the safety, efficacy and optimal dose of psilocybin. Results from the Imperial College London Psilodep-RCT comparing the efficacy and mechanisms of action of psilocybin therapy to the selective serotonin reuptake inhibitor (SSRI) escitalopram will soon be published. However, the efficacy and safety of psilocybin therapy in conjunction with SSRIs in TRD is not yet known. An additional COMPASS study, with a centre in Dublin, will begin to address this question, with potential implications for the future delivery of psilocybin therapy. While at a relatively early stage of clinical development, and notwithstanding the immense challenges of COVID-19, psilocybin therapy has the potential to play an important therapeutic role for various psychiatric disorders in post-COVID-19 clinical psychiatry.

Kelly, J. R., Crockett, M. T., Alexander, L., Haran, M., Baker, A., Burke, L., … & O’Keane, V. (2020). Psychedelic science in post-COVID-19 psychiatry. Irish journal of psychological medicine, 1-6; 10.1017/ipm.2020.94

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Psychedelic Treatments for Psychiatric Disorders: A Systematic Review and Thematic Synthesis of Patient Experiences in Qualitative Studies

Abstract

Introduction: Interest in the use of psychedelic substances for the treatment of mental disorders is increasing. Processes that may affect therapeutic change are not yet fully understood. Qualitative research methods are increasingly used to examine patient accounts; however, currently, no systematic review exists that synthesizes these findings in relation to the use of psychedelics for the treatment of mental disorders.

Objective: To provide an overview of salient themes in patient experiences of psychedelic treatments for mental disorders, presenting both common and diverging elements in patients’ accounts, and elucidating how these affect the treatment process.

Methods: We systematically searched the PubMed, MEDLINE, PsycINFO, and Embase databases for English-language qualitative literature without time limitations. Inclusion criteria were qualitative research design; peer-reviewed studies; based on verbalized patient utterances; and a level of abstraction or analysis of the results. Thematic synthesis was used to analyze and synthesize results across studies. A critical appraisal of study quality and methodological rigor was conducted using the Critical Appraisal Skills Programme (CASP).

Results: Fifteen research articles, comprising 178 patient experiences, were included. Studies exhibited a broad heterogeneity in terms of substance, mental disorder, treatment context, and qualitative methodology. Substances included psilocybin, lysergic acid diethylamide (LSD), ibogaine, ayahuasca, ketamine and 3,4-methylenedioxymethamphetamine (MDMA). Disorders included anxiety, depression, eating disorders, post-traumatic stress disorder, and substance use disorders. While the included compounds were heterogeneous in pharmacology and treatment contexts, patients reported largely comparable experiences across disorders, which included phenomenological analogous effects, perspectives on the intervention, therapeutic processes and treatment outcomes. Comparable therapeutic processes included insights, altered self-perception, increased connectedness, transcendental experiences, and an expanded emotional spectrum, which patients reported contributed to clinically and personally relevant responses.

Conclusions: This review demonstrates how qualitative research of psychedelic treatments can contribute to distinguishing specific features of specific substances, and carry otherwise undiscovered implications for the treatment of specific psychiatric disorders.

Breeksema, J. J., Niemeijer, A. R., Krediet, E., Vermetten, E., & Schoevers, R. A. (2020). Psychedelic treatments for psychiatric disorders: a systematic review and thematic synthesis of patient experiences in qualitative studies. CNS drugs, 1-22; 10.1007/s40263-020-00748-y

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The impact of 3,4-methylendioxymetamphetamine (MDMA) abstinence on seeking behavior and the expression of the D 2-like and mGlu 5 receptors in the rat brain using saturation binding analyses

Abstract

The abundance of research indicates that enriched environment acts as a beneficial factor reducing the risks of relapse in substance use disorder. There is also strong evidence showing the engagement of brain dopaminergic and glutamatergic signaling through the dopamine D2-like and metabotropic glutamate type 5 (mGlu5) receptors, respectively, that has a direct impact on drug reward and drug abstinence. The present study involved 3,4-methylendioxymethamphetamine (MDMA) self-administration with the yoked-triad procedure in rats kept under different housing conditions during abstinence – enriched environment (EE) or isolation cage (IC) conditions – aimed at evaluating changes in brain receptors affecting drug-seeking behavior as well as density and affinity of the D2-like and mGlu5 receptors in several regions of the animal brain. Our results show that exposure to EE conditions strongly reduced active lever presses during cue-induced drug-seeking. At the neurochemical level, we demonstrated marked decreases of D2-like receptor affinity in the dorsal striatum in rats previously self-administering MDMA under EE and increases in density under IC conditions. Moreover, we found the increases in the density and decreases in the affinity of the D2-like receptor in the prefrontal cortex and nucleus accumbens provoked by IC conditions. The mGlu5 receptor density decreased only in the prefrontal cortex after IC and EE abstinence. Moreover, our study has revealed a clear decrease in mGlu5 receptor density in the nucleus accumbens in the group actively administering MDMA only under EE conditions. This study demonstrates that housing conditions have impact on drug-seeking behavior in rats during abstinence from MDMA self-administration. The observed changes in the dopamine D2-like and mGlu5 receptor Bmax and/or Kd values were brain-region specific and related to either pharmacological and/or motivational features of MDMA.

Frankowska, M., Miszkiel, J., Pomierny-Chamiolo, L., Pomierny, B., Celeste Borelli, A., Suder, A., & Filip, M. (2020). The impact of 3,4-methylendioxymetamphetamine (MDMA) abstinence on seeking behavior and the expression of the D2-like and mGlu5 receptors in the rat brain using saturation binding analyses. Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 71(4), 10.26402/jpp.2020.4.09. https://doi.org/10.26402/jpp.2020.4.09

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The rise, fall, and possible rise of LSD

Abstract

LSD and other hallucinogens or psychedelics have been therapeutically used in psychiatry in the period between the Second World War and the late 1980s. In the past years renewed interest in the medical sciences for research and therapeutic use of these substances has evolved. AIM: A discussion of contemporary lsd research in the context of earlier research. METHOD: A systematic survey of the literature on the psychiatric use of lsd and the reactions towards lsd use in society. RESULTS: Since 1947 lsd has been therapeutically used in the treatment of anxiety, depression, addiction, post traumatic disorders, and other conditions. Since the early 1960s this use has been criticized because of the danger of evoking psychoses in patients, and because of the rise of a widespread non-medical use. However, there is no consolidated evidence-base for either the positive or the negative outcomes of lsd therapy. CONCLUSION: At this moment it is unpredictable whether lsd will make a comeback in psychiatry. Contemporary research attempts to evade all public controversy and to build up a solid evidence-base. Nevertheless it demonstrates a direct continuity with earlier research.

Snelders, S., & Pieters, T. (2020). The rise, fall, and possible rise of LSD. Tijdschrift Voor Psychiatrie62(8), 707-712.
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