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Psychiatry

Kappa Opioid Receptor Agonist Mesyl Sal B Attenuates Behavioral Sensitization to Cocaine with Fewer Aversive Side-Effects than Salvinorin A in Rodents.

Abstract

The acute activation of kappa opioid receptors (KOPr) produces antinociceptive and anti-cocaine effects, however, their side-effects have limited further clinical development. Mesyl Sal B is a potent and selective KOPr analogue of Salvinorin A (Sal A), a psychoactive natural product isolated from the plant Salvia divinorum. We assessed the antinociceptive, anti-cocaine, and side-effects of Mesyl Sal B. The anti-cocaine effects are evaluated in cocaine-induced hyperactivity and behavioral sensitization to cocaine in male Sprague Dawley rats. Mesyl Sal B was assessed for anhedonia (conditioned taste aversion), aversion (conditioned place aversion), pro-depressive effects (forced swim test), anxiety (elevated plus maze) and learning and memory deficits (novel object recognition). In male B6.SJL mice, the antinociceptive effects were evaluated in warm-water (50 °C) tail withdrawal and intraplantar formaldehyde (2%) assays and the sedative effects measured with the rotarod performance task. Mesyl Sal B (0.3 mg/kg) attenuated cocaine-induced hyperactivity and behavioral sensitization to cocaine without modulating sucrose self-administration and without producing aversion, sedation, anxiety, or learning and memory impairment in rats. However, increased immobility was observed in the forced swim test indicating pro-depressive effects. Mesyl Sal B was not as potent as Sal A at reducing pain in the antinociceptive assays. In conclusion, Mesyl Sal B possesses anti-cocaine effects, is longer acting in vivo and has fewer side-effects when compared to Sal A, however, the antinociceptive effects are limited.
Kivell, B., Paton, K., Kumar, N., Morani, A., Culverhouse, A., Shepherd, A., … & Prisinzano, T. (2018). Kappa Opioid Receptor Agonist Mesyl Sal B Attenuates Behavioral Sensitization to Cocaine with Fewer Aversive Side-Effects than Salvinorin A in Rodents. Molecules23(10), 2602., 10.3390/molecules23102602
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DARK Classics in Chemical Neuroscience: Ibogaine.

Abstract

The West African iboga plant has been used for centuries by the Bwiti and Mbiri tribes to induce hallucinations during religious ceremonies. Ibogaine, the principal alkaloid responsible for iboga’s psychedelic properties, was isolated and sold as an antidepressant in France for decades before its adverse effects precipitated its removal from the market. An ibogaine resurgence in the 1960s was driven by U.S. heroin addicts who claimed that ibogaine cured their opiate addictions. Behavioral pharmacologic studies in animal models provided evidence that ibogaine could blunt self-administration of not only opiates but cocaine, amphetamines, and nicotine. Ibogaine displays moderate-to-weak affinities for a wide spectrum of receptor and transporter proteins; recent work suggests that its actions at nicotinic acetylcholine receptor subtypes may underlie its reputed antiopiate effects. At micromolar levels, ibogaine is neurotoxic and cardiotoxic and has been linked to several deaths by cardiac arrest. Structure-activity studies led to the isolation of the ibogaine analog 18-methoxycoronaridine (18-MC), an α3β4 nicotinic receptor modulator that retains ibogaine’s anticraving properties with few or no adverse effects. Clinical trials of 18-MC treatment of nicotine addiction are pending. Ibogaine analogs may also hold promise for treating anxiety and depression via the “psychedelic-assisted therapy” approach that employs hallucinogens including psilocybin and methylenedioxymethamphetamine (“ecstasy”).
Wasko, M. J., Witt-Enderby, P. A., & Surratt, C. K. (2018). DARK Classics in Chemical Neuroscience: Ibogaine. ACS chemical neuroscience9(10), 2475-2483., 10.1021/acschemneuro.8b00294
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Increased use of illicit drugs in a Dutch cluster headache population

Abstract

Introduction

Many patients with cluster headache report use of illicit drugs. We systematically assessed the use of illicit drugs and their effects in a well-defined Dutch cluster headache population.

Methods

In this cross-sectional explorative study, 756 people with cluster headache received a questionnaire on lifetime use and perceived effects of illicit drugs. Results were compared with age and sex-matched official data from the Dutch general population.

Results

Compared to the data from the general population, there were more illicit drug users in the cluster headache group (31.7% vs. 23.8%; p < 0.01). Reduction in attack frequency was reported by 56% (n = 22) of psilocybin mushroom, 60% (n = 3) of lysergic acid diethylamide and 50% (n = 2) of heroin users, and a decreased attack duration was reported by 46% (n = 18) of PSI, 50% (n = 2) of heroin and 36% (n = 8) of amphetamine users.

Conclusion

In the Netherlands, people with cluster headache use illicit drugs more often than the general population. The question remains whether this is due to an actual alleviatory effect, placebo response, conviction, or common pathophysiological background between cluster headache and addictive behaviours such as drug use.

de Coo, I. F., Naber, W. C., Wilbrink, L. A., Haan, J., Ferrari, M. D., & Fronczek, R. (2018). Increased use of illicit drugs in a Dutch cluster headache population. Cephalalgia., 10.1177/0333102418804160
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Neurocognitive effects of six ketamine infusions and the association with antidepressant response in patients with unipolar and bipolar depression

Abstract

BACKGROUND:

Ketamine has proven to have rapid, robust antidepressant effects on treatment-resistant depression. However, whether repeated ketamine infusions would cause short-and long-term neurocognitive impairments was not clear. Our aims were to investigate the neurocognitive effects of six ketamine infusions and to examine the association between these infusions and the antidepressant response in patients with unipolar and bipolar depression.

METHODS:

Six intravenous infusions of ketamine (0.5 mg/kg) over a 12-day period were administered to 84 patients with unipolar and bipolar depression. Severity of depressive symptoms and four domains of neurocognition, including speed of processing, working memory, visual learning and verbal learning, were assessed at baseline, one day following the last infusion and again two weeks post-infusion.

RESULTS:

Significant improvements were found on speed of processing ( F=9.344, p<0.001) and verbal learning ( F=5.647, p=0.004) in a linear mixed model. The Sobel test showed significant indirect effects between time and improvement in speed of processing (Sobel test=3.573, p<0.001) as well as improvement in verbal learning (Sobel test=6.649, p<0.001), which were both significantly mediated by change in depressive symptoms. Logistic regression analysis showed ketamine responders had better visual learning at baseline than non-responders (B=0.118, p<0.001).

CONCLUSIONS:

Our findings suggest that neurocognitive function would not deteriorate after six ketamine infusions, while verbal learning and speed of processing improved over 13 days and 26 days of observation, respectively. However, this change was mainly accounted for by improvements in severity of depressive symptoms over time. Greater baseline visual learning predicted an antidepressant response over six ketamine infusions.

Zhou, Y., Zheng, W., Liu, W., Wang, C., Zhan, Y., Li, H., … & Ning, Y. (2018). Neurocognitive effects of six ketamine infusions and the association with antidepressant response in patients with unipolar and bipolar depression. Journal of Psychopharmacology32(10), 1118-1126, 10.1177/0269881118798614
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Psychedelics and the new behaviourism: considering the integration of third-wave behaviour therapies with psychedelic-assisted therapy

This narrative review examines evidence related to the potential for third wave behaviour therapies to serve as adjuncts to psychedelic-assisted therapy. It identifies shared theoretical foundations for both approaches, and notes enhanced mindfulness, decentering, emotion regulation, and distress tolerance as common mechanisms of action. It also identifies potential targets for which both approaches have demonstrated therapeutic potential, including problematic substance use, self-directed and other-directed violence, and mood disorders. Based on these commonalities, there is a call for research on the potential integration of psychedelic-assisted therapy and third wave behaviour therapies including Dialectical Behaviour Therapy, Acceptance and Commitment Therapy, and Mindfulness Based Cognitive Therapy.

Walsh, Z., & Thiessen, M. S. (2018). Psychedelics and the new behaviourism: considering the integration of third-wave behaviour therapies with psychedelic-assisted therapy. International Review of Psychiatry30(4), 343-349., 10.1080/09540261.2018.1474088
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Psychedelics and music: neuroscience and therapeutic implications

From the beginning of therapeutic research with psychedelics, music listening has been consistently used as a method to guide or support therapeutic experiences during the acute effects of psychedelic drugs. Recent findings point to the potential of music to support meaning-making, emotionality, and mental imagery after the administration of psychedelics, and suggest that music plays an important role in facilitating positive clinical outcomes of psychedelic therapy. This review explores the history of, contemporary research on, and future directions regarding the use of music in psychedelic research and therapy, and argues for more detailed and rigorous investigation of the contribution of music to the treatment of psychiatric disorders within the novel framework of psychedelic therapy.
Barrett, F. S., Preller, K. H., & Kaelen, M. (2018). Psychedelics and music: neuroscience and therapeutic implications. International Review of Psychiatry30(4), 350-362., 10.1080/09540261.2018.1484342
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Psychoplastogens: A Promising Class of Plasticity-Promoting Neurotherapeutics

Abstract

Neural plasticity-the ability to change and adapt in response to stimuli-is an essential aspect of healthy brain function and, in principle, can be harnessed to promote recovery from a wide variety of brain disorders. Many neuropsychiatric diseases including mood, anxiety, and substance use disorders arise from an inability to weaken and/or strengthen pathologic and beneficial circuits, respectively, ultimately leading to maladaptive behavioral responses. Thus, compounds capable of facilitating the structural and functional reorganization of neural circuits to produce positive behavioral effects have broad therapeutic potential. Several known drugs and experimental therapeutics have been shown to promote plasticity, but most rely on indirect mechanisms and are slow-acting. Here, I describe psychoplastogens-a relatively new class of fast-acting therapeutics, capable of rapidly promoting structural and functional neural plasticity. Psychoplastogenic compounds include psychedelics, ketamine, and several other recently discovered fast-acting antidepressants. Their use in psychiatry represents a paradigm shift in our approach to treating brain disorders as we focus less on rectifying “chemical imbalances” and place more emphasis on achieving selective modulation of neural circuits.
Olson, D. E. (2018). Psychoplastogens: A Promising Class of Plasticity-Promoting Neurotherapeutics. Journal of experimental neuroscience12, 1179069518800508., 10.1177/1179069518800508
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Repeat-dose ketamine augmentation for treatment-resistant depression with chronic suicidal ideation: A randomized, double blind, placebo controlled trial.

Abstract

BACKGROUND:
Several studies indicate that ketamine has rapid antidepressant effects in patients with treatment-resistant depression (TRD). The extent to which repeated doses of ketamine (versus placebo) reduce depression in the short and long term among outpatients with TRD and chronic, current suicidal ideation remains unknown.
METHODS:
Twenty-six medicated outpatients with severe major depressive disorder with current, chronic suicidal ideation were randomized in a double-blind fashion to six ketamine infusions (0.5 mg/kg over 45 minutes) or saline placebo over three weeks. Depression and suicidal ideation were assessed at baseline, 240 min post-infusion, and during a three-month follow-up phase.
RESULTS:
During the infusion phase, there was no differences in depression severity or suicidal ideation between placebo and ketamine (p = 0.47 and p = 0.32, respectively). At the end of the infusion phase, two patients in the ketamine group and one in the placebo group met criteria for remission of depression. At three-month follow-up, two patients in each group met criteria for remission from depression.
LIMITATIONS:
Limitations include the small sample size, uncontrolled outpatient medication regimens, and restriction to outpatients, which may have resulted in lower levels of suicidal ideation than would be seen in emergency or inpatient settings.
CONCLUSIONS:
Repeated, non-escalating doses of ketamine did not outperform placebo in this double-blind, placebo controlled study of patients with severe TRD and current, chronic suicidal ideation. This result may support our previously published open-label data that, in this severely and chronically ill outpatient population, the commonly used dose of 0.5 mg/kg is not sufficient.
Ionescu, D. F., Bentley, K. H., Eikermann, M., Taylor, N., Johnson-Akeju, O., Swee, M. B., … & Alpert, J. E. (2019). Repeat-dose ketamine augmentation for treatment-resistant depression with chronic suicidal ideation: A randomized, double blind, placebo controlled trial. Journal of Affective Disorders243, 516-524, 10.1016/j.jad.2018.09.037
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Reduction in social anxiety after MDMA-assisted psychotherapy with autistic adults: a randomized, double-blind, placebo-controlled pilot study.

Abstract

RATIONALE:
Standard therapeutic approaches to reduce social anxiety in autistic adults have limited effectiveness. Since 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy shows promise as a treatment for other anxiety disorders, a blinded, placebo-controlled pilot study was conducted.
OBJECTIVES:
To explore feasibility and safety of MDMA-assisted psychotherapy for reduction of social fear and avoidance that are common in the autistic population.
METHODS:
Autistic adults with marked to very severe social anxiety were randomized to receive MDMA (75 to 125 mg, n = 8) or inactive placebo (0 mg, n = 4) during two 8-h psychotherapy sessions (experimental sessions) in a controlled clinical setting. Double-blinded experimental sessions were spaced approximately 1 month apart with 3 non-drug psychotherapy sessions following each. The primary outcome was change in Leibowitz Social Anxiety Scale (LSAS) Total scores from Baseline to one month after the second experimental session. Outcomes were measured again six months after the last experimental session.
RESULTS:
Improvement in LSAS scores from baseline to the primary endpoint was significantly greater for MDMA group compared to the placebo group (P = 0.037), and placebo-subtracted Cohen’s d effect size was very large (d = 1.4, CI - 0.074, 2.874). Change in LSAS scores from baseline to 6-month follow-up showed similar positive results (P = 0.036), with a Cohen’s d effect size of 1.1 (CI - 0.307, 2.527). Social anxiety remained the same or continued to improve slightly for most participants in the MDMA group after completing the active treatment phase.
CONCLUSIONS:
This pilot trial demonstrated rapid and durable improvement in social anxiety symptoms in autistic adults following MDMA-assisted psychotherapy. Initial safety and efficacy outcomes support expansion of research into larger samples to further investigate this novel treatment for social anxiety.
Danforth, A. L., Grob, C. S., Struble, C., Feduccia, A. A., Walker, N., Jerome, L., … & Emerson, A. (2018). Reduction in social anxiety after MDMA-assisted psychotherapy with autistic adults: a randomized, double-blind, placebo-controlled pilot study. Psychopharmacology235(11), 3137-3148., 10.1007/s00213-018-5010-9
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Reduction in social anxiety after MDMA-assisted psychotherapy with autistic adults: a randomized, double-blind, placebo-controlled pilot study.

Abstract

RATIONALE:
Standard therapeutic approaches to reduce social anxiety in autistic adults have limited effectiveness. Since 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy shows promise as a treatment for other anxiety disorders, a blinded, placebo-controlled pilot study was conducted.
OBJECTIVES:
To explore feasibility and safety of MDMA-assisted psychotherapy for reduction of social fear and avoidance that are common in the autistic population.
METHODS:
Autistic adults with marked to very severe social anxiety were randomized to receive MDMA (75 to 125 mg, n = 8) or inactive placebo (0 mg, n = 4) during two 8-h psychotherapy sessions (experimental sessions) in a controlled clinical setting. Double-blinded experimental sessions were spaced approximately 1 month apart with 3 non-drug psychotherapy sessions following each. The primary outcome was change in Leibowitz Social Anxiety Scale (LSAS) Total scores from Baseline to one month after the second experimental session. Outcomes were measured again six months after the last experimental session.
RESU LTS:
Improvement in LSAS scores from baseline to the primary endpoint was significantly greater for MDMA group compared to the placebo group (P = 0.037), and placebo-subtracted Cohen’s d effect size was very large (d = 1.4, CI - 0.074, 2.874). Change in LSAS scores from baseline to 6-month follow-up showed similar positive results (P = 0.036), with a Cohen’s d effect size of 1.1 (CI - 0.307, 2.527). Social anxiety remained the same or continued to improve slightly for most participants in the MDMA group after completing the active treatment phase.
CONCLUSIONS:
This pilot trial demonstrated rapid and durable improvement in social anxiety symptoms in autistic adults following MDMA-assisted psychotherapy. Initial safety and efficacy outcomes support expansion of research into larger samples to further investigate this novel treatment for social anxiety.
Danforth, A. L., Grob, C. S., Struble, C., Feduccia, A. A., Walker, N., Jerome, L., … & Emerson, A. (2018). Reduction in social anxiety after MDMA-assisted psychotherapy with autistic adults: a randomized, double-blind, placebo-controlled pilot study. Psychopharmacology235(11), 3137-3148, 10.1007/s00213-018-5010-9
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