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Anxiety-like behavior induced by salicylate depends on age and can be prevented by a single dose of 5-MeO-DMT

September 17, 2024 / 5-MeO-DMT, Anxiety Disorders / PTSD, Neuroscience, Papers, Substance / Leave a Comment / By / , , , , , , ,

Abstract

Salicylate intoxication is a cause of tinnitus and comorbidly associated with anxiety in humans. In a previous work, we showed that salicylate induces anxiety-like behavior and hippocampal type 2 theta oscillations (theta2) in mice. Here we investigate if the anxiogenic effect of salicylate is dependent on age and previous tinnitus experience. We also tested whether a single dose of DMT can prevent this effect. Using microwire electrode arrays, we recorded local field potential in young (4-5- month-old) and old (11-13-month-old) mice to study the electrophysiological effect of tinnitus in the ventral hippocampus (vHipp) and medial prefrontal cortex (mPFC) in an open field arena and elevated plus maze 1h after salicylate (300mg/kg) injection. We found that anxiety-like behavior and increase in theta2 oscillations (4-6 Hz), following salicylate pre-treatment, only occurs in young (normal hearing) mice. We also show that theta2 and slow gamma oscillations increase in the vHipp and mPFC in a complementary manner during anxiety tests in the presence of salicylate. Finally, we show that pre-treating mice with a single dose of the hallucinogenic 5-MeO-DMT prevents anxiety-like behavior and the increase in theta2 and slow gamma oscillations after salicylate injection in normal hearing young mice. This work further support the hypothesis that anxiety-like behavior after salicylate injection is triggered by tinnitus and require normal hearing. Moreover, our results show that hallucinogenic compounds can be effective in treating tinnitus-related anxiety.

Winne, J., Boerner, B. C., Malfatti, T., Brisa, E., Doerl, J., Nogueira, I., Leão, K. E., & Leão, R. N. (2020). Anxiety-like behavior induced by salicylate depends on age and can be prevented by a single dose of 5-MeO-DMT. Experimental neurology, 326, 113175. https://doi.org/10.1016/j.expneurol.2020.113175

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A qualitative descriptive analysis of effects of psychedelic phenethylamines and tryptamine

January 7, 2020 / DMT, MDMA, Mushrooms / Psilocybin, Papers, Psychology, Publications / By / ,

Abstract

OBJECTIVE:

The number of novel psychedelic phenethylamines and tryptamines has continued to increase, but little academic research has focused on the effects of these substances. We sought to determine and compare the subjective effects of various substances.

METHODS:

We conducted in-depth interviews with 39 adults (75.4% male and 87.2% White) who reported experience using psychedelic phenethylamines and/or tryptamines. Participants described the effects of compounds they have used. We examined the subjective drug effects in a qualitative descriptive manner.

RESULTS:

Participants reported on the use of 36 compounds. The majority (64.1%) reported the use of 2C series drugs, with 2C-B use being most prevalent; 38.5% reported the use of NBOMe, and 25.6% reported the use of DOx. With regard to tryptamines, 46.2% reported use, and 4-AcO-DMT was the most prevalent drug used in this class. 2C-B was often described as being more favorable than other 2C series compounds with the effects described as being comparable with MDMA and LSD. NBOMe effects were generally described in an unfavorable manner, and the effects of DOx were often described as lasting too long (12-36 hr). The effects of 4-AcO-DMT were often described as mimicking psilocybin.

CONCLUSION:

Knowing the effects of various compounds can inform education, prevention, and harm reduction efforts regarding the use of these drugs.

Palamar, J. J., & Acosta, P. (2020). A qualitative descriptive analysis of effects of psychedelic phenethylamines and tryptamines. Human Psychopharmacology: Clinical and Experimental, e2719., 10.1002/hup.2719
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Correlation between the potency of hallucinogens in the mouse head-twitch response assay and their behavioral and subjective effects in other species

January 7, 2020 / DMT, LSD, Neuroscience, Papers, Psychology, Publications / By / , , , ,

Abstract

Serotonergic hallucinogens such as lysergic acid diethylamide (LSD) induce head twitches in rodents via 5-HT2A receptor activation. The goal of the present investigation was to determine whether a correlation exists between the potency of hallucinogens in the mouse head-twitch response (HTR) paradigm and their reported potencies in other species, specifically rats and humans. Dose-response experiments were conducted with phenylalkylamine and tryptamine hallucinogens in C57BL/6J mice, enlarging the available pool of HTR potency data to 41 total compounds. For agents where human data are available (n = 36), a strong positive correlation (r = 0.9448) was found between HTR potencies in mice and reported hallucinogenic potencies in humans. HTR potencies were also found to be correlated with published drug discrimination ED50 values for substitution in rats trained with either LSD (r = 0.9484, n = 16) or 2,5-dimethoxy-4-methylamphetamine (r = 0.9564, n = 21). All three of these behavioral effects (HTR in mice, hallucinogen discriminative stimulus effects in rats, and psychedelic effects in humans) have been linked to 5-HT2A receptor activation. We present evidence that hallucinogens induce these three effects with remarkably consistent potencies. In addition to having high construct validity, the HTR assay also appears to show significant predictive validity, confirming its translational relevance for predicting subjective potency of hallucinogens in humans. These findings support the use of the HTR paradigm as a preclinical model of hallucinogen psychopharmacology and in structure-activity relationship studies of hallucinogens. Future investigations with a larger number of test agents will evaluate whether the HTR assay can be used to predict the hallucinogenic potency of 5-HT2A agonists in humans.

Halberstadt, A. L., Chatha, M., Klein, A. K., Wallach, J., & Brandt, S. D. (2020). Correlation between the potency of hallucinogens in the mouse head-twitch response assay and their behavioral and subjective effects in other species. Neuropharmacology, 107933., 10.1016/j.neuropharm.2019.107933
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The experimental effects of psilocybin on symptoms of anxiety and depression: A meta-analysis.

January 2, 2020 / Anxiety Disorders / PTSD, Depressive Disorders, Mushrooms / Psilocybin, Papers, Psychology, Publications / By / , , , ,

Abstract

The current meta-analysis examined the effects of psilocybin in combination with behavioral interventions on anxiety and depression in samples with elevated symptoms. Across four studies (one uncontrolled; three randomized, placebo-controlled; N = 117), within-group pre-post and pre-follow-up effects on anxiety and depression were large (Hedges’ gs=1.16 to 1.47) and statistically significant. Across three placebo-controlled studies, pre-post placebo-controlled effects were also large (gs = 0.82 to 0.83) and statistically significant. No serious adverse events were reported. Limitations include the small number of studies and risk for bias within studies. Results tentatively support future research on psilocybin for the treatment of anxiety and depression.

Goldberg, S. B., Pace, B. T., Nicholas, C. R., Raison, C. L., & Hutson, P. R. (2020). The experimental effects of psilocybin on symptoms of anxiety and depression: A meta-analysis. Psychiatry Research, 112749., https://doi.org/10.1016/j.psychres.2020.112749
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[Neuroscientific and psychological explanations for the therapeutic effects of psychedelics]

January 1, 2020 / Papers, Psychology, Publications / By /

Abstract

Psychedelics have a strong therapeutic potential for the treatment of biomedical disorders, but the working mechanisms underlying psychedelics are only poorly understood.<br/> AIM: To discuss different mechanisms underlying the therapeutic effects of classic psychedelics.<br/> METHOD: To make a distinction between different levels of explanation: the pharmacological, the neurocognitive and the psychological level.<br/> RESULTS: At the pharmacological level, classic psychedelics affect via the serotonin-receptor, the production of glutamate and brain-derived neurotrophic factor (bdnf), which stimulate neurogenesis. Psychedelics also have anti-flammatory properties and thereby have a protective effect on the brain. At the neurocognitive level, psychedelics have been associated with a reduced activation of the default mode network, which has been implicated in self-referential processing and rumination. At the same time, the brain’s entropy increases, reflected in an increased connectivity between different brain areas. At the psychological level, the therapeutic efficacy of psychedelics has been attributed to the mystical experience, as well as to its awe-inducing potential, the feelings of connectedness and an enhanced awareness of emotions.<br/> CONCLUSION: Psycholytic and psychedelic therapy act at different levels, but ultimately the combination of different mechanisms will help us to understand how psychedelics – in the right set and setting – can be used successfully in therapeutic practice.
van Elk, M. (2020). Neuroscientific and psychological explanations for the therapeutic effects of psychedelics. Tijdschrift Voor Psychiatrie, 62(8), 677-683., https://pubmed.ncbi.nlm.nih.gov/32816296/
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Psychedelics in Western culture: unnecessary psychiatrisation of visionary experiences

September 10, 2024 / Humanities & Art, Papers, Publications, Scienitific Discipline / By /

Abstract

Historical research about the use of psychedelics in specific religious contexts can provide rational explanations for visionary experiences that could otherwise be cause to question the mental health of religious actors. Reversely, if historians ignore or overlook empirical evidence for the use of psychedelics, the result can be that normal and even predictable reactions of healthy subjects to the effects of psychedelic substances are arbitrarily interpreted as ‘irrational’.

AIM: To describe the meaning of the psychedelic factor in historical visionary experiences.

METHOD: Discussion based on three examples of selective use of historical sources on psychedelics.

RESULTS: This theme is of broader relevance to cultural history and scientific theory because we are typically dealing with religious practices that have traditionally been categorized as ‘magic’ and thereby classified in advance as irrational and potentially pathological. The article discusses three historical examples: the so-called Mithras Liturgy from Roman Egypt, early modern witches’ ointments, and spiritual use of hashish in the nineteenth century.

CONCLUSION: Established academics often deny the significance of psychedelics in visionary experiences. Discussion of pre-Enlightenment source material appears to be of considerable importance for the correct interpretation of important religious and cultural traditions. Critical empirical source research without prejudices or implicit agendas is the appropriate method.

Hanegraaff, W. J. (2020). Psychedelics in Western culture: unnecessary psychiatrisation of visionary experiences. Tijdschrift Voor Psychiatrie, 62(8), 713-720.
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Preliminary Report on the Effects of a Low Dose of LSD on Resting-State Amygdala Functional Connectivity.

December 20, 2019 / Anxiety Disorders / PTSD, LSD, Neuroscience, Papers, Psychology, Publications, Substance Use Disorder / By / , , , , , ,

Abstract

BACKGROUND:
The practice of “microdosing,” or the use of repeated, very low doses of lysergic acid diethylamide (LSD) to improve mood or cognition, has received considerable public attention, but empirical studies are lacking. Controlled studies are needed to investigate both the therapeutic potential and the neurobiological underpinnings of this pharmacologic treatment.
METHODS:
The present study was designed to examine the effects of a single low dose of LSD (13 μg) versus placebo on resting-state functional connectivity and cerebral blood flow in healthy young adults. Twenty men and women, 18 to 35 years old, participated in 2 functional magnetic resonance imaging scanning sessions in which they received placebo or LSD under double-blind conditions. During each session, the participants completed drug effect and mood questionnaires, and physiological measures were recorded. During expected peak drug effect, they underwent resting-state blood oxygen level-dependent and arterial spin labeling scans. Cerebral blood flow as well as amygdala and thalamic connectivity were analyzed.
RESULTS:
LSD increased amygdala seed-based connectivity with the right angular gyrus, right middle frontal gyrus, and the cerebellum, and decreased amygdala connectivity with the left and right postcentral gyrus and the superior temporal gyrus. This low dose of LSD had weak and variable effects on mood, but its effects on positive mood were positively correlated with the increase in amygdala-middle frontal gyrus connectivity strength.
CONCLUSIONS:
These preliminary findings show that a very low dose of LSD, which produces negligible subjective changes, alters brain connectivity in limbic circuits. Additional studies, especially with repeated dosing, will reveal whether these neural changes are related to the drug’s purported antidepressant effect.

Copyright © 2019 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Bershad, A. K., Preller, K. H., Lee, R., Keedy, S., Wren-Jarvis, J., Bremmer, M. P., & de Wit, H. (2019). Preliminary report on the effects of a low dose of LSD on resting state amygdalar functional connectivity. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging., https://doi.org/10.1016/j.bpsc.2019.12.007
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Safety, tolerability, pharmacokinetics, and pharmacodynamics of low dose lysergic acid diethylamide (LSD) in healthy older volunteers.

December 18, 2019 / LSD, Neuroscience, Papers, Psychology, Publications / By / , , , ,

Abstract

Research has shown that psychedelics, such as lysergic acid diethylamide (LSD), have profound anti-inflammatory properties mediated by 5-HT2A receptor signaling, supporting their evaluation as a therapeutic for neuroinflammation associated with neurodegenerative disease.
OBJECTIVE:
This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of orally repeated administration of 5 μg, 10 μg, and 20 μg LSD in older healthy individuals. In the current paper, we present safety, tolerability, pharmacokinetics, and pharmacodynamic measures that relate to safety, tolerability, and dose response.
METHODS:
This was a phase 1 double-blind, placebo-controlled, randomized study. Volunteers were randomly assigned to 1 of 4 dose groups (5 μg, 10 μg, 20 μg LSD, and placebo), and received their assigned dose on six occasions (i.e., every 4 days).
RESULTS:
Forty-eight older healthy volunteers (mean age = 62.9 years) received placebo (n = 12), 5 μg (n = 12), 10 μg (n = 12), or 20 μg (n = 12) LSD. LSD plasma levels were undetectable for the 5 μg group and peak blood plasma levels for the 10 μg and 20 μg groups occurred at 30 min. LSD was well tolerated, and the frequency of adverse events was no higher than for placebo. Assessments of cognition, balance, and proprioception revealed no impairment.
CONCLUSIONS:
Our results suggest safety and tolerability of orally administered 5 μg, 10 μg, and 20 μg LSD every fourth day over a 21-day period and support further clinical development of LSD for the treatment and prevention of Alzheimer’s disease (AD).
Family, N., Maillet, E. L., Williams, L. T., Krediet, E., Carhart-Harris, R. L., Williams, T. M., … & Raz, S. (2019). Safety, tolerability, pharmacokinetics, and pharmacodynamics of low dose lysergic acid diethylamide (LSD) in healthy older volunteers. Psychopharmacology, 1-13., https://doi.org/10.1007/s00213-019-05417-7
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