Heavy Cannabis Use, Dependence and the Brain: A Clinical Perspective KROON E., KUHNS L., HOCH E., COUSIJN J. Addictions, 2019 Aug 13. doi: 10.1111/add.14776. PMID: 31408248 Abstract AIMS : To summarize and evaluate our knowledge of the relationship between heavy cannabis use, Cannabis Use Disorder (CUD), and the brain. METHODS : Narrative review of relevant literature identified through existing systematic reviews, meta-analyses and a PubMed search. Epidemiology, clinical representations, potential causal mechanisms, assessments, treatment and prognosis are discussed. RESULTS : Although causality is unclear, heavy and dependent cannabis use is consistently associated with a high prevalence of comorbid psychiatric disorders and learning and memory impairments that seem [...]
Lire la suiteExpanding the Scientific Study of Self-Experience with Psychedelics Manesh Girn and Kalina Christoff Journal of Consciousness Studies, 2018, 25, (11–12), 131–54 Abstract : The nature of the self has long been a topic of discussion in philosophical and religious contexts, and has recently also garnered significant scientific attention. Although evidence exists to suggest the multifaceted nature of self-experience, the amount of research done on each of its putative components has not been uniform. Whereas selfreflective processing has been studied extensively, non-reflective aspects of self-experience have been the subject of comparatively little empirical research. This discrepancy may be linked to the methodological difficulties in experimentally [...]
Lire la suiteSub-acute and long-term effects of ayahuasca on affect and cognitive thinking style and their association with ego dissolution M. V. Uthaug, K. van Oorsouw, K. P. C. Kuypers, M. van Boxtel, N. J. Broers, N. L. Mason, S. W. Toennes, J. Riba, J. G. Ramaekers Psychopharmacology, 2018 https://doi.org/10.1007/s00213-018-4988-3 Abstract Rationale : Ayahuasca is a psychotropic plant tea from South America used for religious purposes by indigenous people of the Amazon. Increasing evidence indicates that ayahuasca may have therapeutic potential in the treatment of mental health disorders and can enhance mindfulness-related capacities. Most research so far has focused on acute and sub-acute effects of ayahuasca on [...]
Lire la suiteMicrodosing psychedelics: More questions than answers? An overview and suggestions for future research Kim P.C. Kuypers, Livia Ng, David Erritzoe, Gitte M. Knudsen, Charles D. Nichols, David E. Nichols, Luca Pani, Anaïs Soula and David Nutt Journal of Psychopharmacology, 2019, 1-10. Doi: 10.1177/0269881119857204 Abstract Background : In the past few years, the issue of ‘microdosing’ psychedelics has been openly discussed in the public arena where claims have been made about their positive effect on mood state and cognitive processes such as concentration. However, there are very few scientific studies that have specifically addressed this issue, and there is no agreed scientific consensus on what microdosing [...]
Lire la suitePositive psychology in the investigation of psychedelics and entactogens : A critical review Henrik Jungaberle, Sascha Thal, Andrea Zeuch, Ansgar Rougemont-Bücking, Maximilian von Heyden, Helena Aicher, Milan Scheidegger Neuropharmacology, 2018 PII: S0028-3908(18)30336-8 DOI: 10.1016/j.neuropharm.2018.06.034 Rationale : We reviewed the concepts and empirical findings in studies with psychedelics and entactogens related to positive psychology – the study of healthy human functioning, well-being and eudaemonia. It is an unresolved question how beneficial effects of psychedelics and entactogens are related to the potential risks of these substances – particularly in non-clinical settings. Methods : We searched in PubMed, PsychINFO and the Cochrane Library for controlled clinical and epidemiological studies [...]
Lire la suiteCultural Neurophenomenology of Psychedelic Thought : Guiding the “Unconstrained” Mind Through Ritual Context Michael Lifshitz, Eli Sheiner, and Laurence J. Kirmayer The Oxford Handbook of Spontaneous Thought : Mind-Wandering, Creativity, and Dreaming, Edited by Kalina Christoff and Kieran C.R. Fox May 2018 DOI: 10.1093/oxfordhb/9780190464745.013.4 Abstract This chapter explores psychedelics as catalysts of spontaneous thought. Classic serotonergic psychedelics such as psilocybin, LSD, and ayahuasca can induce potent alterations in cognition and perception. The chapter reviews research on these substances through the lens of cultural neurophenomenology, which aims to trace how neurobiology and sociocultural factors interact to shape experience. After a decades-long hiatus, the scientific study of psychedelics [...]
Lire la suiteDose-related Effects of Salvinorin A in Humans : Dissociative, Hallucinogenic, and Memory Effects MacLEAN K.A., JOHNSON M.W., REISSIG C.J., PRISINZANO T.E., GRIFFITHS R.R. : Psychopharmacology (Berl), 2013, 226, (2), 381–392. doi: 10.1007/s00213-012-2912-9 Abstract Rationale—Salvinorin A is a kappa opioid agonist and the principal psychoactive constituent of the plant Salvia divinorum, which has increased in popularity as a recreational drug over the past decade. Few human studies have examined salvinorin A. Objective—This double-blind, placebo-controlled study evaluated the dose-related effects of inhaled salvinorin A in individuals with histories of hallucinogen use. Methods—Eight healthy hallucinogen-using adults inhaled up to 16 doses of salvinorin A (0.375 - 21 μg/kg) in ascending order. Physiological, behavioral, [...]
Lire la suiteThe Mechanisms of Psychedelic Visionary Experiences: Hypotheses from Evolutionary Psychology Michael J. Winkelman Frontiers in Neuroscience, 2017, 11, article 539, 1-17. doi: 10.3389/fnins.2017.00539 Neuropharmacological effects of psychedelics have profound cognitive, emotional, and social effects that inspired the development of cultures and religions worldwide. Findings that psychedelics objectively and reliably produce mystical experiences press the question of the neuropharmacological mechanisms by which these highly significant experiences are produced by exogenous neurotransmitter analogs. Humans have a long evolutionary relationship with psychedelics, a consequence of psychedelics’ selective effects for human cognitive abilities, exemplified in the information rich visionary experiences. Objective evidence that psychedelics produce classicmystical experiences, coupled [...]
Lire la suiteUnifying Theories of Psychedelic Drug Effects Link R. Swanson Frontiers in Pharmacology, 2018, Volume 9, Article 172, 1-23 www.frontiersin.org (2 March 2018) doi: 10.3389/fphar.2018.00172 Abstract How do psychedelic drugs produce their characteristic range of acute effects in perception, emotion, cognition, and sense of self? How do these effects relate to the clinical efficacy of psychedelic-assisted therapies? Efforts to understand psychedelic phenomena date back more than a century in Western science. In this article I review theories of psychedelic drug effects and highlight key concepts which have endured over the last 125 years of psychedelic science. First, I describe the subjective phenomenology of acute psychedelic effects using [...]
Lire la suiteRole of the Serotonin 5-HT2A Receptor in Learning John A. Harvey Learning & Memory, 2003, 355-362 www.learnmem.org http://www.learnmem.org/cgi/doi/10.1101/lm.60803. This study reviews the role of the serotonin 5-HT2A receptor in learning as measured by the acquisition of the rabbit’s classically conditioning nictitating membrane response, a component of the eyeblink response. Agonists at the 5-HT2A receptor including LSD (d-lysergic acid diethylamide) enhanced associative learning at doses that produce cognitive effects in humans. Some antagonists such as BOL (d-bromolysergic acid diethylamide), LY53,857, and ketanserin acted as neutral antagonists in that they had no effect on learning, whereas others (MDL11,939, ritanserin, and mianserin) acted as inverse agonists in that [...]
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