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The psychoactive aminoalkylbenzofuran derivatives, 5-APB and 6-APB, mimic the effects of 3,4-methylenedioxyamphetamine (MDA) on monoamine transmission in male rats

Abstract

Rationale: The nonmedical use of new psychoactive substances (NPS) is a worldwide public health concern. The so-called “benzofury” compounds, 5-(2-aminopropyl)benzofuran (5-APB) and 6-(2-aminopropyl)benzofuran (6-APB), are NPS with stimulant-like properties in human users. These substances are known to interact with monoamine transporters and 5-HT receptors in transfected cells, but less is known about their effects in animal models.

Methods: Here, we used in vitro monoamine transporter assays in rat brain synaptosomes to characterize the effects of 5-APB and 6-APB, together with their N-methyl derivatives 5-MAPB and 6-MAPB, in comparison with 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA). In vivo neurochemical and behavioral effects of 5-APB (0.3 and 1.0 mg/kg, i.v.) and 6-APB (0.3 and 1.0 mg/kg, i.v.) were assessed in comparison with MDA (1.0 and 3.0 mg/kg, i.v.) using microdialysis sampling in the nucleus accumbens of conscious male rats.

Results: All four benzofuran derivatives were substrate-type releasers at dopamine transporters (DAT), norepinephrine transporters (NET), and serotonin transporters (SERT) with nanomolar potencies, similar to the profile of effects produced by MDA and MDMA. However, the benzofurans were at least threefold more potent than MDA and MDMA at evoking transporter-mediated release. Like MDA, both benzofurans induced dose-related elevations in extracellular dopamine and serotonin in the brain, but benzofurans were more potent than MDA. The benzofuran derivatives also induced profound behavioral activation characterized by forward locomotion which lasted for at least 2 h post-injection.

Conclusions: Overall, benzofurans are more potent than MDA in vitro and in vivo, producing sustained stimulant-like effects in rats. These data suggest that benzofuran-type compounds may have abuse liability and could pose risks for adverse effects, especially if used in conjunction with abused drugs or medications which enhance monoamine transmission in the brain.

Brandt, S. D., Walters, H. M., Partilla, J. S., Blough, B. E., Kavanagh, P. V., & Baumann, M. H. (2020). The psychoactive aminoalkylbenzofuran derivatives, 5-APB and 6-APB, mimic the effects of 3, 4-methylenedioxyamphetamine (MDA) on monoamine transmission in male rats. Psychopharmacology237(12), 3703-3714; 10.1007/s00213-020-05648-z

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The therapeutic potential of microdosing psychedelics in depression

Abstract

Microdosing psychedelics is the repeated use of small doses of, for example, lysergic acid diethylamide (LSD) and psilocybin, typically for a few weeks. Despite the popular and scientific attention in recent years, and claims by users that it has therapeutic value in affective disorders like depression, little scientific knowledge is available to back this. The purpose of this review was to investigate whether there are scientific grounds to state that this practice could be helpful in the treatment of affective disorders, and safe to use repeatedly. To that end, the literature (PubMed, MedLine) was searched, looking for (controlled) experimental studies with low doses of LSD and/or psilocybin, in healthy volunteers and patient samples. After a selection process and the addition of relevant articles, 14 experimental studies entered this review. Findings show that both LSD (10-20 mcg) and psilocybin (<1-3 mg) have subtle (positive) effects on cognitive processes (time perception, convergent and divergent thinking) and brain regions involved in affective processes. Besides the pleasant experience, increased anxiety and a cycling pattern of depressive and euphoric mood were also found. With regard to safety, it was demonstrated that low doses are well tolerated (in healthy volunteers) and have no-to-minimal effects on physiological measures. While it is yet unclear whether psychedelic microdosing is of therapeutic value for depression, the aforementioned effects on selective processes suggest that low doses of psychedelics could play a role in depression by inducing some kind of cognitive flexibility, which might lead to decreased rumination. While previous studies were conducted mostly in small samples of healthy volunteers, future placebo-controlled clinical trials in depressed patients are required to understand the therapeutic value of microdosing psychedelics, how this differs from therapy using full psychedelic doses, and whether different psychedelics have different effect patterns. The proposed research will give new insights into the potential of future alternative psychiatric treatment forms that are fiercely needed.

Kuypers K. (2020). The therapeutic potential of microdosing psychedelics in depression. Therapeutic advances in psychopharmacology, 10, 2045125320950567. https://doi.org/10.1177/2045125320950567

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Plasma psilocin critically determines behavioral and neurobiological effects of psilocybin

Madsen, M. K., & Knudsen, G. M. (2021). Plasma psilocin critically determines behavioral and neurobiological effects of psilocybin. Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology46(1), 257-258; 10.1038/s41386-020-00823-4
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Ibogaine therapy for addiction: Consumer views from online fora

Abstract

Background Ibogaine is a psychedelic drug used by for-profit clinics and lay-people to treat addiction, despite some reported fatalities and a lack of rigorous clinical research. Little is known about ibogaine therapy from a consumer perspective. Online discussions generate and disseminate information about ibogaine therapy and provide a window into how people understand ibogaine’s risks and uses. We examined views expressed in online fora in order to describe a consumer perspective of ibogaine therapy for addiction, and to elucidate the role of online fora in mediating people’s understanding of, and engagement with ibogaine. Methods We thematically analysed 40 threads comprising posts from 101 individual contributors from two popular online fora; Reddit (n = 20) and Drugs Forum (n = 20). Results Our analysis identified three primary themes: (1) online fora as a resource for do-it-yourself research; (2) the therapeutic interaction in ibogaine therapy, and; (3) therapeutic mechanisms of ibogaine. Online fora were a key resource for information about ibogaine therapy, where personal experiences and evidence-based information were valued. Treatment arrangements, risks, and harm reduction were discussed at length by forum participants. Discussions of therapeutic effects focused on pharmacological mechanisms but positive psychological changes resulting from the psychedelic experience were also reported. Clinic-based treatment was preferred by many forum participants due to safety concerns, but money and time and treatment intent sometimes necessitated lay-administration of ibogaine. Microdosing of ibogaine was also frequently discussed. Conclusion: Online fora appear to have facilitated a sense of community where individuals are held to account for the success of ibogaine therapy. Fora discussions illustrate that neuroscientific explanations of addiction and behaviour have explanatory salience for people involved in ibogaine therapy. Online fora could be used as a platform for clinician and peer-led support and harm-reduction interventions, and for further research monitoring treatment practices and long-term outcomes.

Barber, M., Gardner, J., Savic, M., & Carter, A. (2020). Ibogaine therapy for addiction: Consumer views from online fora. International Journal of Drug Policy83, 102857.; 10.1016/j.drugpo.2020.102857

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Perceived harm, motivations for use and subjective experiences of recreational psychedelic 'magic' mushroom use

Abstract

Background: Data on actual harm of magic mushrooms suggest that toxicity and abuse potential is low, however, their legal status suggests otherwise. We aimed to gauge perception of harm of magic mushrooms in both users and mushroom-naïve participants. We also aimed to observe differences in expectations of effects between users and mushroom-naïve participants, and whether motivations for use predicted their expected effects.

Method: In total, 73 polydrug users with experience of using magic mushrooms and 78 mushroom-naïve participants completed an online survey. We asked participants to rank a list of 10 substances from most dangerous to least dangerous and questioned them about expectation of effect using a modified magic mushroom expectation questionnaire. Users were asked about their motivations for using magic mushrooms.

Results: Both groups perceive mushrooms to be safer than heroin, cocaine, prescription painkillers, gamma-hydroxybutyrate (GHB), ecstasy, tobacco and alcohol. However, the mushroom-naïve group ranked mushrooms as significantly more dangerous than the user group. Non-users reported greater expectancy for negative intoxication. Users reported greater expected entactogenic, prosocial, aesthetic and mood effects, and perceptual alterations. Finally, expectant effects of mushroom use were associated with different motivations for use, for example using for personal psychotherapy was associated with expectation of increased entactogenic effects and decreased negative effects.

Conclusion: Our data suggest a general perception of harm that is in line with data on actual harm, but at odds with current legal classifications. Future clinical investigations may require management of negative intoxication expectation of participants with no prior experience of psilocybin.

Roberts, C. A., Osborne-Miller, I., Cole, J., Gage, S. H., & Christiansen, P. (2020). Perceived harm, motivations for use and subjective experiences of recreational psychedelic ‘magic’mushroom use. Journal of Psychopharmacology34(9), 999-1007; 10.1177/0269881120936508
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In vitro structure-activity relationship determination of 30 psychedelic new psychoactive substances by means of β-arrestin 2 recruitment to the serotonin 2A receptor

Abstract

Serotonergic psychedelics, substances exerting their effects primarily through the serotonin 2A receptor (5-HT2AR), continue to comprise a substantial portion of reported new psychoactive substances (NPS). The exact mechanisms of action of psychedelics still remain to be elucidated further, and certain pathways remain largely unexplored on a molecular level for this group of compounds. A systematic comparison of substances belonging to different subclasses, monitoring the receptor-proximal β-arrestin 2 recruitment, is lacking. Based on a previously reported in vitro bioassay employing functional complementation of a split nanoluciferase to monitor β-arrestin 2 recruitment to the 5-HT2AR, we here report on the setup of a stable HEK 293 T cell-based bioassay. Following verification of the performance of this new stable cell system as compared to a system based on transient transfection, the stable expression system was deemed suitable for the pharmacological characterization of psychedelic NPS. Subsequently, it was applied for the in vitro assessment of the structure-activity relationship of a set of 30 substances, representing different subclasses of phenylalkylamine psychedelics, among which 12 phenethylamine derivatives (2C-X), 7 phenylisopropylamines (DOx) and 11 N-benzylderivatives (25X-NB). The resulting potency and efficacy values provide insights into the structure-activity relationship of the tested compounds, overall confirm findings observed with other reported in vitro assays, and even show a significant correlation with estimated common doses. This approach, in which a large series of psychedelic NPS belonging to different subclasses is comparatively tested, using a same assay setup, monitoring a receptor-proximal event, not only gives pharmacological insights, but may also allow prioritization of legal actions related to the most potent -and potentially dangerous- compounds.

Pottie, E., Cannaert, A., & Stove, C. P. (2020). In vitro structure–activity relationship determination of 30 psychedelic new psychoactive substances by means of β-arrestin 2 recruitment to the serotonin 2A receptor. Archives of Toxicology94(10), 3449-3460; 10.1007/s00204-020-02836-w
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Esketamine Nasal Spray for Rapid Reduction of Major Depressive Disorder Symptoms in Patients Who Have Active Suicidal Ideation With Intent: Double-Blind, Randomized Study (ASPIRE I)

Abstract

Objective: To compare esketamine to placebo, each in addition to standard-of-care treatment, for rapidly reducing major depressive disorder symptoms, including suicidal ideation.
Methods: This phase 3, double-blind, multicenter study (ASPIRE I), conducted between June 2017 and December 2018, enrolled 226 adults having major depressive disorder based on Diagnostic and Statistical Manual of Mental Disorders fifth edition (DSM-5) criteria, active suicidal ideation with intent, and need for psychiatric hospitalization. Patients were randomized 1:1 to esketamine 84 mg or placebo nasal spray twice-weekly for 4 weeks, each with comprehensive standard-of-care treatment (initial psychiatric hospitalization and newly initiated or optimized oral antidepressant[s] therapy). Change from baseline to 24 hours post-first dose in Montgomery-Asberg Depression Rating Scale (MADRS) total score (primary endpoint) was analyzed using analysis of covariance (ANCOVA), and change in Clinical Global Impression of Severity of Suicidality Revised version (CGI-SS-r; key secondary endpoint) score was analyzed using ANCOVA on ranks with treatment difference estimated using the Hodges-Lehmann estimate.
Results: Greater improvement in MADRS total score was observed with esketamine + standard-of-care versus placebo + standard-of-care at 24 hours (least-squares mean difference [SE]: -3.8 [1.39]; 95% CI, -6.56 to -1.09; 2-sided P = .006), as well as at earlier (4 hours) and later time points during 4-week double-blind treatment. The difference between groups in the severity of suicidality was not statistically significant (median of treatment difference [95% CI]: 0.0 [-1.00 to 0.00]; 2-sided P = .107). The most common adverse events among esketamine-treated patients were dizziness, dissociation, headache, nausea, and somnolence.
Conclusions: These findings demonstrate rapid and robust efficacy of esketamine nasal spray in reducing depressive symptoms in severely ill patients with major depressive disorder who have active suicidal ideation with intent.
Fu, D. J., Ionescu, D. F., Li, X., Lane, R., Lim, P., Sanacora, G., … & Canuso, C. M. (2020). Esketamine nasal spray for rapid reduction of major depressive disorder symptoms in patients who have active suicidal ideation with intent: double-blind, randomized study (ASPIRE I). The Journal of clinical psychiatry81(3), 0-0., https://doi.org/10.4088/jcp.19m13191
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Chronic pain and psychedelics: a review and proposed mechanism of action

Abstract

The development of chronic pain is a complex mechanism that is still not fully understood. Multiple somatic and visceral afferent pain signals, when experienced over time, cause a strengthening of certain neural circuitry through peripheral and central sensitization, resulting in the physical and emotional perceptual chronic pain experience. The mind-altering qualities of psychedelics have been attributed, through serotonin 2A (5-HT2A) receptor agonism, to ‘reset’ areas of functional connectivity (FC) in the brain that play prominent roles in many central neuropathic states. Psychedelic substances have a generally favorable safety profile, especially when compared with opioid analgesics. Clinical evidence to date for their use for chronic pain is limited; however, several studies and reports over the past 50 years have shown potential analgesic benefit in cancer pain, phantom limb pain and cluster headache. While the mechanisms by which the classic psychedelics may provide analgesia are not clear, several possibilities exist given the similarity between 5-HT2A activation pathways of psychedelics and the nociceptive modulation pathways in humans. Additionally, the alterations in FC seen with psychedelic use suggest a way that these agents could help reverse the changes in neural connections seen in chronic pain states. Given the current state of the opioid epidemic and limited efficacy of non-opioid analgesics, it is time to consider further research on psychedelics as analgesics in order to improve the lives of patients with chronic pain conditions.
Castellanos, J. P., Woolley, C., Bruno, K. A., Zeidan, F., Halberstadt, A., & Furnish, T. (2020). Chronic pain and psychedelics: a review and proposed mechanism of action. Regional Anesthesia & Pain Medicine., http://dx.doi.org/10.1136/rapm-2020-101273
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Exposure-Response Analysis to Assess the Concentration-QTc Relationship of Psilocybin/Psilocin

Abstract

Psilocybin is being developed for treating major depressive disorder. Psilocybin is readily dephosphorylated to psilocin upon absorption. The potential for psilocin proarrhythmic effect was assessed using a concentration-QTc interval (C-QTc) analysis from an open-label single ascending dose study of psilocybin. Psilocybin doses ranged from 0.3 to 0.6 mg/kg. This trial showed a significant but shallow C-QTc relationship. At the clinical dose of 25 mg, the mean psilocin maximum concentration is 18.7 ng/mL, and the associated mean (upper 90% confidence interval of mean) QTcF change is 2.1 (6.6) milliseconds. Given the short half-life of psilocin of about 4 hours, there would be no accumulation after monthly oral doses used in clinical trials. The upper limit of the 90% confidence interval of the model-predicted mean ΔQTcF crossed 10 milliseconds at a psilocin concentration of 31.1 ng/mL. At a supraclinical psilocin maximum concentration of about 60 ng/mL, ΔQTcF remains low, with a mean (upper limit of the 90% confidence interval) of 9.1 (17.9) milliseconds. This analysis enabled the characterization of the C-QTc relationship and prediction of QTc prolongation at the expected clinical and possible higher psilocybin doses.

Dahmane, E., Hutson, P. R., & Gobburu, J. V. (2020). Exposure‐Response Analysis to Assess the Concentration‐QTc Relationship of Psilocybin/Psilocin. Clinical Pharmacology in Drug Development.; 10.1002/cpdd.796

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Long-term effects of psychedelic drugs: A systematic review

Abstract

Research into the basic effects and therapeutic applications of psychedelic drugs has grown considerably in recent years. Yet, pressing questions remain regarding the substances’ lasting effects. Although individual studies have begun monitoring sustained changes, no study to-date has synthesized this information. Therefore, this systematic review aims to fill this important gap in the literature by synthesizing results from 34 contemporary experimental studies which included classic psychedelics, human subjects, and follow-up latencies of at least two weeks. The bulk of this work was published in the last five years, with psilocybin being the most frequently administered drug. Enduring changes in personality/attitudes, depression, spirituality, anxiety, wellbeing, substance misuse, meditative practices, and mindfulness were documented. Mystical experiences, connectedness, emotional breakthrough, and increased neural entropy were related to these long-term changes in psychological functioning. Finally, with proper screening, preparation, supervision, and integration, limited aversive side effects were noted by study participants. Future researchers should focus on including larger and more diverse samples, lengthier longitudinal designs, stronger control conditions, and standardized dosages.

Aday, J. S., Mitzkovitz, C. M., Bloesch, E. K., Davoli, C. C., & Davis, A. K. (2020). Long-term effects of psychedelic drugs: A systematic review. Neuroscience & Biobehavioral Reviews., 10.1016/j.neubiorev.2020.03.017
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30 April - Q&A with Rick Strassman

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