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The current state of research on ayahuasca: A systematic review of human studies assessing psychiatric symptoms, neuropsychological functioning, and neuroimaging

June 10, 2016 / Ayahuasca, Papers, Psychology, Publications, Substance Use Disorder / By / , , ,

Abstract

RATIONALE: In recent decades, the use of ayahuasca (AYA) – a β-carboline- and dimethyltryptamine-rich hallucinogenic botanical preparation traditionally used by Northwestern Amazonian tribes for ritual and therapeutic purposes – has spread from South America to Europe and the USA, raising concerns about its possible toxicity and hopes of its therapeutic potential. Thus, it is important to analyze the acute, subacute, and long-term effects of AYA to assess its safety and toxicity.

OBJECTIVES: The purpose of this study was to conduct a systematic review of human studies assessing AYA effects on psychiatric symptoms, neuropsychological functioning, and neuroimaging.

METHODS: Papers published until 16 December 2015 were included from PubMed, LILACS and SciELO databases following a comprehensive search strategy and pre-determined set of criteria for article selection.

RESULTS: The review included 28 full-text articles. Acute AYA administration was well tolerated, increased introspection and positive mood, altered visual perceptions, activated frontal and paralimbic regions and decreased default mode network activity. It also improved planning and inhibitory control and impaired working memory, and showed antidepressive and antiaddictive potentials. Long-term AYA use was associated with increased cortical thickness of the anterior cingulate cortex and cortical thinning of the posterior cingulate cortex, which was inversely correlated to age of onset, intensity of prior AYA use, and spirituality. Subacute and long-term AYA use was not associated with increased psychopathology or cognitive deficits, being associated with enhanced mood and cognition, increased spirituality, and reduced impulsivity.

CONCLUSIONS: Acute, subacute, and long-term AYA use seems to have low toxicity. Preliminary studies about potential therapeutic effects of AYA need replication due to their methodological limitations.

dos Santos, R. G., Balthazar, F. M., Bouso, J. C., & Hallak, J. E. (2016). The current state of research on ayahuasca: A systematic review of human studies assessing psychiatric symptoms, neuropsychological functioning, and neuroimaging. Journal of Psychopharmacology, 0269881116652578.

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Magic mushroom compound is a potential treatment for patients with major depression

June 8, 2016 / Depressive Disorders, Mushrooms / Psilocybin, Papers, Psychology, Publications / By /

Abstract

A hallucinogenic compound derived from magic mushrooms could provide a new route for antidepressant research.

Carhart-Harris, R. L. Magic mushroom compound is a potential treatment for patients with major depression. http://dx.doi.org/10.7748/ns.30.41.15.s18
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Potential involvement of serotonergic signaling in ketamine’s antidepressant actions: A critical review

June 2, 2016 / Depressive Disorders, Ketamine, Neuroscience, Papers, Psychology, Publications / By / , , , , ,

Abstract

A single i.v. infusion of ketamine, classified as an N-methyl-d-aspartate (NMDA) receptor antagonist, may alleviate depressive symptoms within hours of administration in treatment resistant depressed patients, and the antidepressant effect may last for several weeks. These unique therapeutic properties have prompted researchers to explore the mechanisms mediating the antidepressant effects of ketamine, but despite many efforts, no consensus on its antidepressant mechanism of action has been reached. Recent preclinical reports have associated the neurotransmitter serotonin (5-hydroxytryptamine; 5-HT) with the antidepressant-like action of ketamine. Here, we review the current evidence for a serotonergic role in ketamine’s antidepressant effects.

The pharmacological profile of ketamine may include equipotent activity on several non-NMDA targets, and the current hypotheses for the mechanisms responsible for ketamine’s antidepressant activity do not appear to preclude the possibility that non-glutamate neurotransmitters are involved in the antidepressant effects. At multiple levels, the serotonergic and glutamatergic systems interact, and such crosstalk could support the notion that changes in serotonergic neurotransmission may impact ketamine’s antidepressant potential. In line with these prospects, ketamine may increase 5-HT levels in the prefrontal cortex of rats, plausibly via hippocampal NMDA receptor inhibition and activation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors. In addition, a number of preclinical studies suggest that the antidepressant-like effects of ketamine may depend on endogenous activation of 5-HT receptors. Recent imaging and behavioral data predominantly support a role for 5-HT1A or 5-HT1B receptors, but the full range of 5-HT receptors has currently not been systematically investigated in this context. Furthermore, the nature of any 5-HT dependent mechanism in ketamine’s antidepressant effect is currently not understood, and therefore, more studies are warranted to confirm this hypothesis and explore the specific pathways that might implicate 5-HT.

du Jardin, K. G., Müller, H. K., Elfving, B., Dale, E., Wegener, G., & Sanchez, C. (2016). Potential involvement of serotonergic signaling in ketamine’s antidepressant actions: A critical review. Progress in Neuro-Psychopharmacology and Biological Psychiatry. http://dx.doi.org/10.1016/j.pnpbp.2016.05.007
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Potential involvement of serotonergic signaling in ketamine's antidepressant actions: A critical review

June 2, 2016 / Depressive Disorders, Ketamine, Neuroscience, Papers, Psychology, Publications / By / , , , , ,

Abstract

A single i.v. infusion of ketamine, classified as an N-methyl-d-aspartate (NMDA) receptor antagonist, may alleviate depressive symptoms within hours of administration in treatment resistant depressed patients, and the antidepressant effect may last for several weeks. These unique therapeutic properties have prompted researchers to explore the mechanisms mediating the antidepressant effects of ketamine, but despite many efforts, no consensus on its antidepressant mechanism of action has been reached. Recent preclinical reports have associated the neurotransmitter serotonin (5-hydroxytryptamine; 5-HT) with the antidepressant-like action of ketamine. Here, we review the current evidence for a serotonergic role in ketamine’s antidepressant effects.

The pharmacological profile of ketamine may include equipotent activity on several non-NMDA targets, and the current hypotheses for the mechanisms responsible for ketamine’s antidepressant activity do not appear to preclude the possibility that non-glutamate neurotransmitters are involved in the antidepressant effects. At multiple levels, the serotonergic and glutamatergic systems interact, and such crosstalk could support the notion that changes in serotonergic neurotransmission may impact ketamine’s antidepressant potential. In line with these prospects, ketamine may increase 5-HT levels in the prefrontal cortex of rats, plausibly via hippocampal NMDA receptor inhibition and activation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors. In addition, a number of preclinical studies suggest that the antidepressant-like effects of ketamine may depend on endogenous activation of 5-HT receptors. Recent imaging and behavioral data predominantly support a role for 5-HT1A or 5-HT1B receptors, but the full range of 5-HT receptors has currently not been systematically investigated in this context. Furthermore, the nature of any 5-HT dependent mechanism in ketamine’s antidepressant effect is currently not understood, and therefore, more studies are warranted to confirm this hypothesis and explore the specific pathways that might implicate 5-HT.

du Jardin, K. G., Müller, H. K., Elfving, B., Dale, E., Wegener, G., & Sanchez, C. (2016). Potential involvement of serotonergic signaling in ketamine’s antidepressant actions: A critical review. Progress in Neuro-Psychopharmacology and Biological Psychiatry. http://dx.doi.org/10.1016/j.pnpbp.2016.05.007
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The potential use of ayahuasca in psychiatry

June 1, 2016 / Ayahuasca, Papers, Psychology, Publications / By / , , ,

Abstract

Ayahuasca is a decoctum made of admixture plants containing dimethyltryptamine and harmine. For millennia it has been used as a central element of spiritual, religious, initiation, and other – foremost healing – rituals, originally by the indigenous groups of the Amazon basin and later by the mestizo populations of the region. During the last two decades the brew has raised increased scientific and lay interest about its healing potentials within the framework of Western therapeutic settings. The typical ayahuasca effects consist of strong somatic reactions, vivid visions, relived personal memories, cathartic emotions, and insightful, introspective experiences when the emerging mental contents take different context and get deeper perspectives. The ayahuasca-experience can be exhausting necessitating the presence of an experienced leader for helping participants to pass difficult phases and for maximizing therapeutic benefits. No health damaging adverse effect has been confirmed thus far as result of its well-structured, institutionalized use. The scientific investigation of ayahuasca is hindered by legal issues, methodical problems, and sociocultural preconceptions. The present review outlines the therapeutic potentials of ayahuasca use in psychiatry with its psychobiological and spiritual background.

Frecska, E., Bokor, P., Andrassy, G., & Kovacs, A. (2016). The potential use of ayahuasca in psychiatry. Neuropsychopharmacologia Hungarica: a Magyar Pszichofarmakologiai Egyesulet lapja= official journal of the Hungarian Association of Psychopharmacology, 18(2), 79.
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Efficacy and safety of oral ketamine versus diclofenac to alleviate mild to moderate depression in chronic pain patients: A double-blind, randomized, controlled trial

June 1, 2016 / Depressive Disorders, Ketamine, Papers, Psychology, Publications / By / , , , , , ,

Abstract

Background: Ketamine is a glutamate N-methyl-d-aspartate receptor antagonist capable of exerting antidepressive effects in single or repeated intravenous infusions. The objective of this study was to investigate the safety and the efficacy of oral ketamine vs. diclofenac monotherapy in reducing symptoms of mild to moderate depression among patients with chronic pain.

Methods: This study is a 6-week, randomized, double-blind, controlled, parallel-group trial with two intervention arms (ketamine, fixed daily dosage of 150 mg vs. diclofenac, fixed daily dosage of 150 mg). Twenty participants in each arm completed the trial program all of whom had two post-baseline measurements at week 3 and week 6. Reduction in depression symptoms was assessed using the Hamilton Depression Rating Scale (HDRS) and the hospital anxiety and depression subscale for depression (HADSDepression) scores at baseline and week 3 and week 6 post-intervention.

Results: Significantly lower HDRS scores were observed in the ketamine treatment group as early as 6 weeks post-intervention (P=0.008). By comparison, mean (±standard deviation) HADS depression subscale scores were significantly lower for individuals receiving ketamine compared to diclofenac for both post-baseline measures at week 3 (6.95±1.47 vs. 8.40±1.6, P=0.005) and week 6 (6.20±1.15 vs. 7.35±1.18, p=0.003).

Limitations: The limitations of the present study were its small sample size and the short-term follow-up period.

Conclusions: Oral ketamine appears to be a safe and effective option in improving depressive symptoms of patients with chronic pain with mild-to-moderate depression.

Jafarinia, M., Afarideh, M., Tafakhori, A., Arbabi, M., Ghajar, A., Noorbala, A. A., … & Akhondzadeh, S. (2016). Efficacy and Safety of Oral Ketamine versus Diclofenac to Alleviate Mild to Moderate Depression in Chronic Pain Patients: A Double-Blind, Randomized, Controlled Trial. Journal of Affective Disorders. http://dx.doi.org/10.1016/j.jad.2016.05.076

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Using the Theory of Planned Behavior to predict implementation of harm reduction strategies among MDMA/ecstasy users

June 1, 2016 / MDMA, Papers, Psychology, Publications, Substance Use Disorder / By / ,

Abstract

This prospective study was designed to test whether the variables proposed by the Theory of Planned Behavior (TPB) were associated with baseline intention to implement and subsequent use of 2 MDMA/ecstasy-specific harm reduction interventions: preloading/postloading and pill testing/pill checking. Using targeted Facebook advertisements, an international sample of 391 recreational ecstasy users were recruited to complete questionnaires assessing their ecstasy consumption history, and their attitudes, subjective norms, perceived behavioral control, habit strength (past strategy use), and intention to use these two strategies. Attitudes, subjective norms, and perceived behavioral control were significantly associated with baseline intention to preload/postload and pill test/pill check. Out of the 391 baseline participants, 100 completed the two-month follow-up assessment. Baseline habit strength and frequency of ecstasy consumption during the three months prior to baseline were the only significant predictors of how often participants used the preloading/postloading strategy during the follow-up. Baseline intention to pill test/pill check was the only significant predictor of how often participants used this strategy during the follow-up. These findings provide partial support for TPB variables as both correlates of baseline intention to implement and predictors of subsequent use of these two strategies. Future investigations could assess whether factors related to ecstasy consumption (e.g., subjective level of intoxication, craving, negative consequences following consumption), and environmental factors (e.g., accessibility and availability of harm reduction resources) improve the prediction of how often ecstasy users employ these and other harm reduction strategies.

Davis, A. K., & Rosenberg, H. (2016). Using the Theory of Planned Behavior to predict implementation of harm reduction strategies among MDMA/ecstasy users. Psychology of Addictive Behaviors, 30(4), 500.  http://dx.doi.org/10.1037/adb0000167
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LSD Acutely Impairs Fear Recognition and Enhances Emotional Empathy and Sociality

June 1, 2016 / LSD, Papers, Psychology, Publications / By / , , , ,

Abstract

Lysergic acid diethylamide (LSD) is used recreationally and has been evaluated as an adjunct to psychotherapy to treat anxiety in patients with life-threatening illness. LSD is well-known to induce perceptual alterations, but unknown is whether LSD alters emotional processing in ways that can support psychotherapy. We investigated the acute effects of LSD on emotional processing using the Face Emotion Recognition Task (FERT) and Multifaceted Empathy Test (MET). The effects of LSD on social behavior were tested using the Social Value Orientation (SVO) test. Two similar placebo-controlled, double-blind, random-order, cross-over studies were conducted using 100 μg LSD in 24 subjects and 200 μg LSD in 16 subjects. All of the subjects were healthy and mostly hallucinogen-naive 25- to 65-year-old volunteers (20 men, 20 women). LSD produced feelings of happiness, trust, closeness to others, enhanced explicit and implicit emotional empathy on the MET, and impaired the recognition of sad and fearful faces on the FERT. LSD enhanced the participants’ desire to be with other people and increased their prosocial behavior on the SVO test. These effects of LSD on emotion processing and sociality may be useful for LSD-assisted psychotherapy.

Dolder, P. C., Schmid, Y., Müller, F., Borgwardt, S., & Liechti, M. E. (2016). Lsd acutely impairs fear recognition and enhances emotional empathy and sociality. Neuropsychopharmacology. http://dx.doi.org/10.1038/npp.2016.82
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Ibogaine and addiction in the animal model, a systematic review and meta-analysis

May 31, 2016 / Iboga / Ibogaine, Neuroscience, Papers, Psychology, Publications, Substance Use Disorder / By / , , , , ,

Abstract

Ibogaine is a naturally occurring substance which has been increasingly used in the lay-scene to reduce craving and relapse in patients with substance use disorders (SUDs). Although human clinical trials on the safety and efficacy of ibogaine are lacking, animal studies do support the efficacy of ibogaine. In this systematic review and meta-analysis (MA), we summarise these animal findings, addressing three questions: (1) does ibogaine reduce addictive behaviour in animal models of SUDs?; (2) what are the toxic effects of ibogaine on motor functioning, cerebellum and heart rhythm?; (3) what are neuropharmacological working mechanisms of ibogaine treatment in animal models of SUDs? MA of 27 studies showed that ibogaine reduced drug self-administration, particularly during the first 24 h after administration. Ibogaine had no effect on drug-induced conditioned place preference. Ibogaine administration resulted in motor impairment in the first 24 h after supplementation, and cerebral cell loss even weeks after administration. Data on ibogaines effect on cardiac rhythm, as well as on its neuropharmacological working mechanisms are limited. Our results warrant further studies into the clinical efficacy of ibogaine in SUD patients in reducing craving and substance use, but close monitoring of the patients is recommended because of the possible toxic effects. In addition, more work is needed to unravel the neuropharmacological working mechanisms of ibogaine and to investigate its effects on heart rhythm.

Belgers, M., Leenaars, M., Homberg, J. R., Ritskes-Hoitinga, M., Schellekens, A. F. A., & Hooijmans, C. R. (2016). Ibogaine and addiction in the animal model, a systematic review and meta-analysis. Translational psychiatry, 6(5), e826. http://dx.doi.org/10.1038/tp.2016.71
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±3,4-Methylenedioxymethamphetamine: Treating PTSD in The Modern World

May 26, 2016 / Anxiety Disorders / PTSD, MDMA, Papers, Psychology, Publications / By /

Abstract

Post-traumatic stress disorder (PTSD) is a serious condition that afflicts millions of individuals in the United States. Its complexity has resulted in physicians struggling to effectively implement and maintain treatment. Emerging studies suggest that ±3,4-Methylenedioxymethamphetamine (MDMA), or “ecstasy”, may prove beneficial in treating PTSD in combination with conventional psychotherapy. By acting on the 5-HT transporter in the brain, MDMA has been found to have positive effects on brain activity; encouraging neuroplasticity through the accumulation of brain-derived neurotrophic factor (BDNF). Integrating psychoactive drugs into polytrauma therapy will broaden our understanding of the components involved in maintaining wellness in the human psyche.

Baxter, A. (2016). ±3, 4-Methylenedioxymethamphetamine: Treating PTSD in The Modern World.
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