OPEN Foundation

Psychology

Psilocybin, psychological distress, and suicidality

Abstract

Hendricks et al. (2015) found that having ever used any classic psychedelic substance—namely, dimethyltryptamine (DMT), ayahuasca, lysergic acid diethylamide (LSD), mescaline, peyote or San Pedro, or psilocybin—was associated with a significantly reduced likelihood of past month psychological distress (weighted OR = .81 (.72–.91)), past year suicidal thinking (weighted OR = .86 (.78–.94)), past year suicidal planning (weighted OR = .71 (.54–.94)), and past year suicide attempt (weighted OR = .64 (.46–.89)) in the United States adult population. Although these findings comport with an emerging literature suggesting classic psychedelics may be effective in the treatment of mental health conditions and prevention of self-harm, they do not speak to the potential risk profile or therapeutic applications of psilocybin in particular, which is the most commonly examined classic psychedelic in contemporary clinical research. Considering that psilocybin may be a candidate for future approved medical use in the United States, the United Kingdom, and other nations (Bogenschutz et al., 2015; Grob et al., 2011; Johnson et al., 2014; see also Nutt et al., 2013), an analysis of the specific relationships of psilocybin use with psychological distress and suicidality may help inform decisions by the United States Food and Drug Administration and regulatory bodies of other nations. The objectives of the current research, therefore, were to extend the analysis of Hendricks et al. (2015) by evaluating the associations of lifetime psilocybin use, per se, with past month psychological distress, past year suicidal thinking, past year suicidal planning, and past year suicide attempt in the United States adult population.

Hendricks, P. S., Johnson, M. W., & Griffiths, R. R. (2015). Psilocybin, psychological distress, and suicidality. Journal of Psychopharmacology, 29(9), 1041-1043. http://dx.doi.org/10.1177/0269881115598338
Link to full text

R-ketamine: a rapid-onset and sustained antidepressant without psychotomimetic side effects

Abstract

Although the efficacy of racemate ketamine, a rapid onset and sustained antidepressant, for patients with treatment-resistant depression was a serendipitous finding, clinical use of ketamine is limited, due to psychotomimetic side effects and abuse liability. Behavioral and side-effect evaluation tests were applied to compare the two stereoisomers of ketamine. To elucidate their potential therapeutic mechanisms, we examined the effects of these stereoisomers on brain-derived neurotrophic factor (BDNF)-TrkB signaling, and synaptogenesis in selected brain regions. In the social defeat stress and learned helplessness models of depression, R-ketamine showed a greater potency and longer-lasting antidepressant effect than S-ketamine (esketamine). Furthermore, R-ketamine induced a more potent beneficial effect on decreased dendritic spine density, BDNF-TrkB signaling and synaptogenesis in the prefrontal cortex (PFC), CA3 and dentate gyrus (DG) of the hippocampus from depressed mice compared with S-ketamine. However, neither stereoisomer affected these alterations in the nucleus accumbens of depressed mice. In behavioral tests for side effects, S-ketamine, but not R-ketamine, precipitated behavioral abnormalities, such as hyperlocomotion, prepulse inhibition deficits and rewarding effects. In addition, a single dose of S-ketamine, but not R-ketamine, caused a loss of parvalbumin (PV)-positive cells in the prelimbic region of the medial PFC and DG. These findings suggest that, unlike S-ketamine, R-ketamine can elicit a sustained antidepressant effect, mediated by increased BDNF-TrkB signaling and synaptogenesis in the PFC, DG and CA3. R-ketamine appears to be a potent, long-lasting and safe antidepressant, relative to S-ketamine, as R-ketamine appears to be free of psychotomimetic side effects and abuse liability.

Yang, C., Shirayama, Y., Zhang, J. C., Ren, Q., Yao, W., Ma, M., … & Hashimoto, K. (2015). R-ketamine: a rapid-onset and sustained antidepressant without psychotomimetic side effects. Translational psychiatry, 5(9), e632. http://dx.doi.org/10.1038/tp.2015.136

Link to full text

Recreational 3,4-methylenedioxy-N-methylamphetamine (MDMA) or ‘ecstasy’ and self-focused compassion: Preliminary steps in the development of a therapeutic psychopharmacology of contemplative practices

Abstract

3,4-methylenedioxy-N-methylamphetamine (MDMA) produces diverse pro-social effects. Cognitive training methods rooted in Eastern contemplative practices also produce these effects through the development of a compassionate mindset. Given this similarity, we propose that one potential mechanism of action of MDMA in psychotherapy is through enhancing effects on intrapersonal attitudes (i.e. pro-social attitudes towards the self). We provide a preliminary test of this idea. Recreational MDMA (ecstasy) users were tested on two occasions, having consumed or not consumed ecstasy. Self-critical and self-compassionate responses to self-threatening scenarios were assessed before (T1) and after (T2) ecstasy use (or non-use), and then after compassionate imagery (T3). Moderating roles of dispositional self-criticism and avoidant attachment were examined. Separately, compassionate imagery and ecstasy produced similar sociotropic effects, as well as increases in self-compassion and reductions in self-criticism. Higher attachment-related avoidance was associated with additive effects of compassionate imagery and ecstasy on self-compassion. Findings were in line with MDMA’s neuropharmacological profile, its phenomenological effects and its proposed adjunctive use in psychotherapy. However, although conditions were balanced, the experiment was non-blind and MDMA dose/purity was not determined. Controlled studies with pharmaceutically pure MDMA are still needed to test these effects rigorously.

Kamboj, S. K., Kilford, E. J., Minchin, S., Moss, A., Lawn, W., Das, R. K., … & Freeman, T. P. (2015). Recreational 3, 4-methylenedioxy-N-methylamphetamine (MDMA) or ‘ecstasy’and self-focused compassion: preliminary steps in the development of a therapeutic psychopharmacology of contemplative practices. Journal of Psychopharmacology, 0269881115587143.

Link to full text

Recreational 3,4-methylenedioxy-N-methylamphetamine (MDMA) or 'ecstasy' and self-focused compassion: Preliminary steps in the development of a therapeutic psychopharmacology of contemplative practices

Abstract

3,4-methylenedioxy-N-methylamphetamine (MDMA) produces diverse pro-social effects. Cognitive training methods rooted in Eastern contemplative practices also produce these effects through the development of a compassionate mindset. Given this similarity, we propose that one potential mechanism of action of MDMA in psychotherapy is through enhancing effects on intrapersonal attitudes (i.e. pro-social attitudes towards the self). We provide a preliminary test of this idea. Recreational MDMA (ecstasy) users were tested on two occasions, having consumed or not consumed ecstasy. Self-critical and self-compassionate responses to self-threatening scenarios were assessed before (T1) and after (T2) ecstasy use (or non-use), and then after compassionate imagery (T3). Moderating roles of dispositional self-criticism and avoidant attachment were examined. Separately, compassionate imagery and ecstasy produced similar sociotropic effects, as well as increases in self-compassion and reductions in self-criticism. Higher attachment-related avoidance was associated with additive effects of compassionate imagery and ecstasy on self-compassion. Findings were in line with MDMA’s neuropharmacological profile, its phenomenological effects and its proposed adjunctive use in psychotherapy. However, although conditions were balanced, the experiment was non-blind and MDMA dose/purity was not determined. Controlled studies with pharmaceutically pure MDMA are still needed to test these effects rigorously.

Kamboj, S. K., Kilford, E. J., Minchin, S., Moss, A., Lawn, W., Das, R. K., … & Freeman, T. P. (2015). Recreational 3, 4-methylenedioxy-N-methylamphetamine (MDMA) or ‘ecstasy’and self-focused compassion: preliminary steps in the development of a therapeutic psychopharmacology of contemplative practices. Journal of Psychopharmacology, 0269881115587143.

Link to full text

Effects of LSD on grooming behavior in serotonin transporter heterozygous (Sert+/−) mice

Abstract

Serotonin (5-HT) plays a crucial role in the brain, modulating mood, cognition and reward. The serotonin transporter (SERT) is responsible for the reuptake of 5-HT from the synaptic cleft and regulates serotonin signaling in the brain. In humans, SERT genetic variance is linked to the pathogenesis of various psychiatric disorders, including anxiety, autism spectrum disorders (ASD) and obsessive–compulsive disorder (OCD). Rodent self-grooming is a complex, evolutionarily conserved patterned behavior relevant to stress, ASD and OCD. Genetic ablation of mouse Sert causes various behavioral deficits, including increased anxiety and grooming behavior. The hallucinogenic drug lysergic acid diethylamide (LSD) is a potent serotonergic agonist known to modulate human and animal behavior. Here, we examined heterozygous Sert+/− mouse behavior following acute administration of LSD (0.32 mg/kg). Overall, Sert+/− mice displayed a longer duration of self-grooming behavior regardless of LSD treatment. In contrast, LSD increased serotonin-sensitive behaviors, such as head twitching, tremors and backwards gait behaviors in both Sert+/+ and Sert+/− mice. There were no significant interactions between LSD treatment and Sert gene dosage in any of the behavioral domains measured. These results suggest that Sert+/− mice may respond to the behavioral effects of LSD in a similar manner to wild-type mice.

Kyzar, E. J., Stewart, A. M., & Kalueff, A. V. (2016). Effects of LSD on grooming behavior in serotonin transporter heterozygous (Sert+/−) mice. Behavioural brain research, 296, 47-52. http://dx.doi.org/10.1016/j.bbr.2015.08.018
Link to full text

MDMA, cannabis, and cocaine produce acute dissociative symptoms

Abstract

Some drugs of abuse may produce dissociative symptoms, but this aspect has been understudied. We explored the dissociative potential of three recreational drugs (3,4-methylenedioxymethamphetamine (MDMA), cannabis, and cocaine) during intoxication and compared their effects to literature reports of dissociative states in various samples. Two placebo-controlled studies were conducted. In Study 1 (N=16), participants received single doses of 25, 50, and 100 mg of MDMA, and placebo. In Study 2 (N=21), cannabis (THC 300 µg/kg), cocaine (HCl 300 mg), and placebo were administered. Dissociative symptoms as measured with the Clinician-Administered Dissociative States Scale (CADSS) significantly increased under the influence of MDMA and cannabis. To a lesser extent, this was also true for cocaine. Dissociative symptoms following MDMA and cannabis largely exceeded those observed in schizophrenia patients, were comparable with those observed in Special Forces soldiers undergoing survival training, but were lower compared with ketamine-induced dissociation. Cocaine produced dissociative symptoms that were comparable with those observed in schizophrenia patients, but markedly less than those in Special Forces soldiers and ketamine users. Thus, MDMA and cannabis can produce dissociative symptoms that resemble dissociative pathology. The study of drug induced dissociation is important, because it may shed light on the mechanisms involved in dissociative psychopathology.

van Heugten-Van der Kloet, D., Giesbrecht, T., van Wel, J., Bosker, W. M., Kuypers, K. P., Theunissen, E. L., … & Ramaekers, J. G. (2015). MDMA, cannabis, and cocaine produce acute dissociative symptoms. Psychiatry research, 228(3), 907-912. http://dx.doi.org/10.1016/j.psychres.2015.04.028

Link to full text

The mixed serotonin receptor agonist psilocybin reduces threat-induced modulation of amygdala connectivity

Abstract

Stimulation of serotonergic neurotransmission by psilocybin has been shown to shift emotional biases away from negative towards positive stimuli. We have recently shown that reduced amygdala activity during threat processing might underlie psilocybin’s effect on emotional processing. However, it is still not known whether psilocybin modulates bottom-up or top-down connectivity within the visual-limbic-prefrontal network underlying threat processing. We therefore analyzed our previous fMRI data using dynamic causal modeling and used Bayesian model selection to infer how psilocybin modulated effective connectivity within the visual–limbic–prefrontal network during threat processing. First, both placebo and psilocybin data were best explained by a model in which threat affect modulated bidirectional connections between the primary visual cortex, amygdala, and lateral prefrontal cortex. Second, psilocybin decreased the threat-induced modulation of top-down connectivity from the amygdala to primary visual cortex, speaking to a neural mechanism that might underlie putative shifts towards positive affect states after psilocybin administration. These findings may have important implications for the treatment of mood and anxiety disorders.

Kraehenmann, R., Schmidt, A., Friston, K., Preller, K. H., Seifritz, E., & Vollenweider, F. X. (2015). The mixed serotonin receptor agonist psilocybin reduces threat-induced modulation of amygdala connectivity. NeuroImage: Clinical. https://dx.doi.org/10.1016/j.nicl.2015.08.009
Link to full text

Noribogaine is a G-Protein Biased κ-Opioid Receptor Agonist

Abstract

Noribogaine is the long-lived human metabolite of the anti-addictive substance ibogaine. Noribogaine efficaciously reaches the brain with concentrations up to 20 μM after acute therapeutic dose of 40 mg/kg ibogaine in animals. Noribogaine displays atypical opioid-like components in vivo, anti-addictive effects and potent modulatory properties of the tolerance to opiates for which the mode of action remained uncharacterized thus far. Our binding experiments and computational simulations indicates that noribogaine may bind to the orthosteric morphinan binding site of the opioid receptors. Functional activities of noribogaine at G-protein and non G-protein pathways of the mu and kappa opioid receptors were characterized. Noribogaine was a weak mu antagonist with a functional inhibition constants (Ke) of 20 μM at the G-protein and β-arrestin signaling pathways. Conversely, noribogaine was a G-protein biased kappa agonist 75% as efficacious as dynorphin A at stimulating GDP-GTP exchange (EC50 = 9 μM) but only 12% as efficacious at recruiting β-arrestin, which could contribute to the lack of dysphoric effects of noribogaine. In turn, noribogaine functionally inhibited dynorphin-induced kappa β-arrestin recruitment and was more potent than its G-protein agonistic activity with an IC50 of 1 μM. This biased agonist/antagonist pharmacology is unique to noribogaine in comparison to various other ligands including ibogaine, 18-MC, nalmefene, and 6’-GNTI. We predict noribogaine to promote certain analgesic effects as well as anti-addictive effects at effective concentrations >1 μM in the brain. Because elevated levels of dynorphins are commonly observed and correlated with anxiety, dysphoric effects, and decreased dopaminergic tone, a therapeutically relevant functional inhibition bias to endogenously released dynorphins by noribogaine might be worthy of consideration for treating anxiety and substance related disorders.

Maillet, E. L., Milon, N., Heghinian, M. D., Fishback, J., Schürer, S. C., Garamszegi, N., & Mash, D. C. (2015). Noribogaine is a G-Protein Biased κ-Opioid Receptor Agonist. Neuropharmacology. https://dx.doi.org/10.1016/j.neuropharm.2015.08.032
Link to full text

5-HT2A and mGlu2/3 receptor interactions: on their relevance to cognitive function and psychosis

Abstract

Serotonin [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][5-hydroxytryptamine (5-HT)] and glutamate have both been implicated in the pathophysiology of neuropsychiatric disorders but also in the mechanism of antipsychotic and hallucinogenic drug actions. Furthermore, close antagonistic interactions between 5-HT2A and metabotropic glutamate (mGlu)2/3 receptors have been established over the last decades on the basis of numerous electrophysiological, biochemical, and behavioral studies. Besides synaptic mechanisms, more recent findings suggested that heterodimeric 5-HT2A-mGlu2 receptor complexes in the prefrontal cortex may account for the functional crosstalk between these two receptor subtypes. In this review, we focus on in-vitro and in-vivo studies documenting the important relationship between 5-HT2A and mGlu2/3 receptors, with relevance to both normal behavioral function and psychosis.

Wischhof, L., & Koch, M. (2015). 5-HT2A and mGlu2/3 receptor interactions: on their relevance to cognitive function and psychosis. Behavioural pharmacology. https://dx.doi.org/10.1097/FBP.0000000000000183
Link to full text

[/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]

LSD enhances the emotional response to music

Abstract

RATIONALE:

There is renewed interest in the therapeutic potential of psychedelic drugs such as lysergic acid diethylamide (LSD). LSD was used extensively in the 1950s and 1960s as an adjunct in psychotherapy, reportedly enhancing emotionality. Music is an effective tool to evoke and study emotion and is considered an important element in psychedelic-assisted psychotherapy; however, the hypothesis that psychedelics enhance the emotional response to music has yet to be investigated in a modern placebo-controlled study.

OBJECTIVES:

The present study sought to test the hypothesis that music-evoked emotions are enhanced under LSD.

METHODS:

Ten healthy volunteers listened to five different tracks of instrumental music during each of two study days, a placebo day followed by an LSD day, separated by 5-7 days. Subjective ratings were completed after each music track and included a visual analogue scale (VAS) and the nine-item Geneva Emotional Music Scale (GEMS-9).

RESULTS:

Results demonstrated that the emotional response to music is enhanced by LSD, especially the emotions “wonder”, “transcendence”, “power” and “tenderness”.

CONCLUSIONS:

These findings reinforce the long-held assumption that psychedelics enhance music-evoked emotion, and provide tentative and indirect support for the notion that this effect can be harnessed in the context of psychedelic-assisted psychotherapy. Further research is required to test this link directly.

Kaelen, M., Barrett, F. S., Roseman, L., Lorenz, R., Family, N., Bolstridge, M., … & Carhart-Harris, R. L. (2015). LSD enhances the emotional response to music. Psychopharmacology, 1-8. https://dx.doi.org/10.1007/s00213-015-4014-y
Link to full text

Online Event - Psychedelic Care in Recreational Settings - 3 October 2024

X

interested in becoming a trained psychedelic-assisted therapist?