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Classical hallucinogens and neuroimaging: A systematic review of human studies: Hallucinogens and neuroimaging

/ Ayahuasca, DMT, LSD, Mescaline / Cacti, Mushrooms / Psilocybin, Neuroscience, Papers, Publications / / , , ,

Abstract

Serotonergic hallucinogens produce alterations of perceptions, mood, and cognition, and have anxiolytic, antidepressant, and antiaddictive properties. These drugs act as agonists of frontocortical 5-HT2A receptors, but the neural basis of their effects are not well understood. Thus, we conducted a systematic review of neuroimaging studies analyzing the effects of serotonergic hallucinogens in man. Studies published in the PubMed, Lilacs, and SciELO databases until 12 April 2016 were included using the following keywords: “ayahuasca”, “DMT”, “psilocybin”, “LSD”, “mescaline” crossed one by one with the terms “mri”, “fmri”, “pet”, “spect”, “imaging” and “neuroimaging”. Of 279 studies identified, 25 were included. Acute effects included excitation of frontolateral/frontomedial cortex, medial temporal lobe, and occipital cortex, and inhibition of the default mode network. Long-term use was associated with thinning of the posterior cingulate cortex, thickening of the anterior cingulate cortex, and decreased neocortical 5-HT2A receptor binding. Despite the high methodological heterogeneity and the small sample sizes, the results suggest that hallucinogens increase introspection and positive mood by modulating brain activity in the fronto-temporo-parieto-occipital cortex.

dos Santos, R. G., Osório, F. L., Crippa, J. A. S., & Hallak, J. E. (2016). Classical hallucinogens and neuroimaging: A systematic review of human studies: Hallucinogens and neuroimaging. Neuroscience & Biobehavioral Reviews, 71, 715-728. 10.1016/j.neubiorev.2016.10.026
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Classic Psychedelics and Rational Suicide in the Elderly: Exploring the Potential Utility of a Reemerging Treatment Paradigm

/ Ayahuasca, DMT, LSD, Mescaline / Cacti, Papers, Psychology, Publications / / ,

Abstract

The objective of the current chapter is to evaluate the potential utility of classic psychedelics including dimethyltryptamine (found in the Amazonian plant decoction ayahuasca), lysergic acid diethylamide (LSD), mescaline (found in peyote and other psychoactive cacti), and psilocybin (found in certain mushrooms) in addressing rational suicide among the elderly. An overview of the sociopolitical history of classic psychedelics is presented, followed by an examination of empirical findings pertaining to rational suicide. This chapter concludes that classic psychedelics may counteract rational suicide among the elderly by promoting the perception that life is worth living even in the face of great adversity and encourages future study on this important topic.

Hendricks, P. S., & Grob, C. S. (2017). Classic Psychedelics and Rational Suicide in the Elderly: Exploring the Potential Utility of a Reemerging Treatment Paradigm. In Rational Suicide in the Elderly (pp. 203-210). Springer International Publishing. 10.1007/978-3-319-32672-6_14

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Role of psilocybin in the treatment of depression

/ Depressive Disorders, Mushrooms / Psilocybin, Papers, Psychology, Publications / / ,

Abstract

Psilocybin is a naturally occurring alkaloid, pharmacologically similar to the classic hallucinogen lysergic acid diethylamide (LSD). Although primarily used as a recreational drug or an entheogen in particular cultural settings, recent population based studies have shown that it does not lead to serious physical or mental health problems or dependent use. In view of recent work demonstrating psilocybin’s potential to increase subjective sense of wellbeing and because of its novel mechanism of 5-HT2A serotonin receptor agonism, it is being explored for possible therapeutic utility in mood and anxiety disorders.

Mahapatra, A., & Gupta, R. (2016). Role of psilocybin in the treatment of depression. Therapeutic Advances in Psychopharmacology, 2045125316676092.
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Of Roots and Fruits A Comparison of Psychedelic and Nonpsychedelic Mystical Experiences

/ Papers, Psychology, Publications / / , , , , , ,

Abstract

Experiences of profound existential or spiritual significance can be triggered reliably through psychopharmacological means using psychedelic substances. However, little is known about the benefits of religious, spiritual, or mystical experiences (RSMEs) prompted by psychedelic substances, as compared with those that occur through other means. In this study, 739 self-selected participants reported the psychological impact of their RSMEs and indicated whether they were induced by a psychedelic substance. Experiences induced by psychedelic substances were rated as more intensely mystical (d = .75, p < .001), resulted in a reduced fear of death (d = .21, p < .01), increased sense of purpose (d = .18, p < .05), and increased spirituality (d = .28, p < .001) as compared with nonpsychedelically triggered RSMEs. These results remained significant in an expanded model controlling for gender, education, socioeconomic status, and religious affiliation. These findings lend support to the growing consensus that RSMEs induced with psychedelic substances are genuinely mystical and generally positive in outcome.

Yaden, D. B., Le Nguyen, K. D., Kern, M. L., Belser, A. B., Eichstaedt, J. C., Iwry, J., … & Newberg, A. B. (2016). Of Roots and Fruits A Comparison of Psychedelic and Nonpsychedelic Mystical Experiences. Journal of Humanistic Psychology, 0022167816674625.
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Ecstatic Landscapes: The Manifestation of Psychedelic Art

/ Ayahuasca, LSD, Mushrooms / Psilocybin, Papers, Publications / /

Abstract

“Psychedelic art” can be defined as artwork manifested in the context of the ingestion of LSD-type drugs and related substances. There is a long history of such work dating back to ancient times (picturing mushrooms and other plants with psychedelic effects) as well as more recent anecdotal first-person accounts and various collections of psychological data resulting from experiments and interviews. One such collection includes the studies by Krippner of over 200 artists, writers, and musicians who referred to their artistic productions as “psychedelic” because they had some connection with their occasional or frequent use of these substances. Although there were no commonalities characterizing all of their paintings, films, poems, novels, songs, or other works, several frequent themes were noted following content analysis of the interview reports. The results of this group of studies, as well as those of more structured explorations, attests to the importance of this topic for humanistic psychology with its emphasis upon creativity, human potential, and exploring the wide range of human experience.
Krippner, S. (2016). Ecstatic Landscapes: The Manifestation of Psychedelic Art. Journal of Humanistic Psychology, 0022167816671579.
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Medicine, religion and ayahuasca in Catalonia. Considering ayahuasca networks from a medical anthropology perspective

/ Anthropology & Sociology, Ayahuasca, Papers, Psychiatry & Medicine, Publications / / ,

Abstract

Ayahuasca is a psychoactive beverage from the Amazon, traditionally used by indigenous and mestizo populations in the region. Widespread international use of the beverage began in the 1990s in both secular contexts and religious/spiritual networks. This article offers an analysis of these networks as health care systems in general and for the case of Spain and specifically Catalonia, describing the emergence and characteristics of their groups, and the therapeutic itineraries of some participants. The medical anthropology perspective we take enables us to reflect on the relationship between medicine and religion, and problematize the tensions between medicalization and medical pluralism. Closely linked to the process of medicalization, we also analyze prohibitionist drug policies and their tensions and conflicts with the use of ayahuasca in ritual and ‘health care’ contexts. The paper ends with a reflection on the problem of ayahuasca as ‘medicine’, since the connection between religion and medicine is a very difficult one to separate.

Apud, I., & Romaní, O. (2017). Medicine, religion and ayahuasca in Catalonia. Considering ayahuasca networks from a medical anthropology perspective. International Journal of Drug Policy, 39, 28-36. 10.1016/j.drugpo.2016.07.011
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Antidepressant, anxiolytic and procognitive effects of subacute and chronic ketamine in the chronic mild stress model of depression

/ Depressive Disorders, Ketamine, Papers, Psychology, Publications / / , , ,

Abstract

Ketamine is the prototype of a new generation of antidepressant drugs, which is reported in clinical studies to be effective in treatment-resistant patients, with an effect that appears within hours and lasts for a few days. Chronic mild stress (CMS) is a well-established and widely used animal model of depression, in which anhedonia, anxiogenesis and cognitive dysfunction can be observed reliably. Studies using acute or brief ketamine treatment following withdrawal from CMS have replicated the clinical finding of a rapid onset of antidepressant action. However, there have been no CMS studies of chronic daily ketamine treatment or continued stress following ketamine treatment, which would have greater translational potential in relation to the long-term maintenance of antidepressant effects. Wistar rats were drug treated following an initial 2 weeks of CMS exposure, which continued alongside daily drug treatment. A first experiment tested a range of chronic (5 weeks) ketamine doses (5-30 mg/kg); a second compared the effects of subacute (3-5 days) and chronic (5 weeks) treatment. CMS-induced anhedonic, anxiogenic and dyscognitive effects, as measured, respectively, by decreased sucrose intake, avoidance of open arms in the elevated plus maze and loss of discrimination in the novel object recognition test. A sustained antidepressant-like effect of ketamine in the sucrose intake test was observed in both experiments, with an onset at around 1 week, faster than imipramine, and an optimum dose of 10 mg/kg. Anxiogenic and dyscognitive effects of CMS, in the elevated plus maze and novel object recognition test, respectively, were fully reversed by both subacute and chronic ketamine treatment. Daily treatment with ketamine in the CMS model causes sustained long-term antidepressant, anxiolytic and procognitive effects. The demonstration of a procognitive effect of ketamine may have particular translational value.

Papp, M., Gruca, P., Lason-Tyburkiewicz, M., & Willner, P. (2016). Antidepressant, anxiolytic and procognitive effects of subacute and chronic ketamine in the chronic mild stress model of depression. Behavioural Pharmacology. 10.1097/FBP.0000000000000259

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Alterations of consciousness and mystical-type experiences after acute LSD in humans

/ LSD, Papers, Psychology, Publications / / , ,

Abstract

Rationale: Lysergic acid diethylamide (LSD) is used recreationally and in clinical research. Acute mystical-type experiences that are acutely induced by hallucinogens are thought to contribute to their potential therapeutic effects. However, no data have been reported on LSD-induced mystical experiences and their relationship to alterations of consciousness. Additionally, LSD dose- and concentration-response functions with regard to alterations of consciousness are lacking.

Methods: We conducted two placebo-controlled, double-blind, cross-over studies using oral administration of 100 and 200 μg LSD in 24 and 16 subjects, respectively. Acute effects of LSD were assessed using the 5 Dimensions of Altered States of Consciousness (5D-ASC) scale after both doses and the Mystical Experience Questionnaire (MEQ) after 200 μg.

Results: On the MEQ, 200 μg LSD induced mystical experiences that were comparable to those in patients who underwent LSD-assisted psychotherapy but were fewer than those reported for psilocybin in healthy subjects or patients. On the 5D-ASC scale, LSD produced higher ratings of blissful state, insightfulness, and changed meaning of percepts after 200 μg compared with 100 μg. Plasma levels of LSD were not positively correlated with its effects, with the exception of ego dissolution at 100 μg.

Conclusions: Mystical-type experiences were infrequent after LSD, possibly because of the set and setting used in the present study. LSD may produce greater or different alterations of consciousness at 200 μg (i.e., a dose that is currently used in psychotherapy in Switzerland) compared with 100 μg (i.e., a dose used in imaging studies). Ego dissolution may reflect plasma levels of LSD, whereas more robustly induced effects of LSD may not result in such associations.

Liechti, M. E., Dolder, P. C., & Schmid, Y. (2016). Alterations of consciousness and mystical-type experiences after acute LSD in humans. Psychopharmacology, 1-12. 10.1007/s00213-016-4453-0

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Activation of 5-HT2A/2C receptors reduces the excitability of cultured cortical neurons

/ Neuroscience, Papers, Publications / / , , , , ,

Abstract

The abundant forebrain serotonergic projections are believed to modulate the activities of cortical neurons. 5-HT2 receptor among multiple subtypes of serotonin receptors contributes to the modulation of excitability, synaptic transmissions and plasticity. In the present study, whole-cell patch-clamp recording was adopted to examine whether activation of 5-HT2A/2C receptors would have any impact on the excitability of cultured cortical neurons. We found that 2,5-Dimethoxy-4-iodoamphetamine (DOI), a selective 5-HT2A/2C receptor agonist, rapidly and reversibly depressed spontaneous action potentials mimicking the effect of serotonin. The decreased excitability was also observed for current-evoked firing. Additionally DOI increased neuronal input resistance. Hyperpolarization-activated cyclic nucleotide-gated cationic channels (HCN) did not account for the inhibition of spontaneous firing. The synaptic contribution was ruled out in that DOI augmented excitation and attenuated inhibition to actually favor an increase in the excitability. Our findings revealed that activation of 5-HT2A/2C receptors reduces neuronal excitability, which would deepen our understanding of serotonergic modulation of cortical activities.
Hu, L., Liu, C., Dang, M., Luo, B., Guo, Y., & Wang, H. (2016). Activation of 5-HT 2A/2C receptors reduces the excitability of cultured cortical neurons. Neuroscience letters, 632, 124-129. 10.1016/j.neulet.2016.08.052
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Psychological effects of MDMA

/ MDMA, Papers, Psychology, Publications / /

Abstract

Zinberg’s Interaction Model implies that the content of a drug-induced experience is a function of the pharmacological properties of the drug, the set (the user’s characteristics e.g. motivation and personality), and the setting (the physical and social context). The current research investigated the function of the set and setting and their role in shaping the psychological effects of 3,4-methylenedioxmethamphetamine (MDMA), as well as their role in reducing the risk of drug abuse.
An online survey was distributed among adult MDMA polydrug users (n = 158) and MDMA-naïve controls (alcohol, nicotine and cannabis users, n = 138). Participants answered questions regarding their pattern of drug use, their motivation for MDMA use and the setting (e.g. clubbing, home with friends), as well as the subjective effects of MDMA. Participants also completed a range of self-report measures of self-reflection and insight, emotional intelligence, and personality, as well as a drug dependency measure.
MDMA users displayed higher levels of self-reflection and insight, openness to new experience and lower levels of neuroticism and conscientiousness, in comparison to the control group. The significant predictors of self-reflection and insight were openness, emotional intelligence, MDMA use, extraversion and neuroticism. When the analysis was rerun only for the MDMA group, the significant predictors of self-reflection and insight were openness, emotional intelligence and self-insight effects of MDMA. High levels of self-reported negative effects of MDMA were predictors of a problematic drug use.
These findings suggest that there might be a relationship between MDMA use and higher levels of self-reflection and insight; however, longitudinal studies are required to further investigate the causality of this relationship. The results add to existing evidence that MDMA has potential for altering emotional experiences. Further research utilising a prospective design is warranted.

Wieliczko, M. J. (2016). Psychological effects of MDMA (Doctoral dissertation, Canterbury Christ Church University).

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Healing culture and its somewhat humorous discontents - July 22

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