Open-label study of consecutive ibogaine and 5-MeO-DMT assisted-therapy for trauma-exposed male Special Operations Forces Veterans: prospective data from a clinical program in Mexico

A multi-institutional investigation of psilocybin's effects on mouse behavior

Studies reporting novel therapeutic effects of psychedelic drugs are rapidly emerging. However, the reproducibility and reliability of these findings could remain uncertain for years. Here, we implemented a multi-institutional collaborative approach to define the robust and replicable effects of the psychedelic drug psilocybin on mouse behavior. Five laboratories performed the same experiments to test the acute and persistent effects of psilocybin (2 mg/kg, IP) on various behaviors that psychedelics have been proposed to affect, including anxiety-related approach-avoidance, exploration, sociability, depression-related behaviors, fear extinction, and social reward learning. Through this coordinated approach, we found that psilocybin had several robust and replicable acute effects on mouse behavior, including increased anxiety- and avoidance-related behaviors and decreased fear expression. Surprisingly, however, we found that psilocybin did not have replicable effects 24 hours post psilocybin administration on reducing anxiety- and depression-like behaviors or facilitating fear extinction learning. Additionally, we were unable to observe psilocybin-induced alterations in social preference or social reward learning. Overall, our comprehensive characterization of psilocybin's acute and persistent behavioral effects using ∼200 total male and female mice per experiment spread across five independent labs demonstrates with unique certainty several acute drug effects and suggests that psilocybin's persistent effects in mice may be more modest and inconsistent than previously suggested. We believe this unusual multi-laboratory, highly coordinated research effort serves as a model for facilitating the generation of replicable results and consequently will reduce efforts based on unreliable and spurious results.

Psychedelics and Suicide-Related Outcomes: A Systematic Review

Background/Objectives: Suicide accounts for 1.4% of global deaths, and the slow-acting nature of traditional treatments for suicide risk underscores the need for alternatives. Psychedelic therapies may rapidly reduce suicide risk. This systematic review evaluates impact of psychedelic therapies on suicide-related outcomes. Methods: A systematic search of MEDLINE, Embase, PsycINFO, and ClinicalTrials.gov was conducted up to November 2024. Results: Four randomized controlled trials (RCTs) evaluated suicidality as a secondary outcome or safety measure, showing significant reductions in suicidal ideation with psilocybin (three studies) and MDMA-assisted therapy (MDMA-AT; one study). Effect sizes, measured by Cohen's d, ranged from =0.52 to 1.25 (p = 0.01 to 0.005), with no safety issues reported. Five additional RCTs assessed suicidality as a safety measure, showing reductions in suicidal ideation with psilocybin (two studies) and MDMA-AT (three studies; p = 0.02 to 0.04). Among 24 non-randomized and cross-sectional studies, results were mixed. Psilocybin (three studies) reduced suicidal ideation, with odds ratios (OR) of 0.40-0.75. MDMA-AT (five studies in PTSD patients) had a pooled effect size of d = 0.61 (95% CI: 0.32-0.89). LSD (six studies) showed increased odds of suicidality, with odds ratios ranging from 1.15 to 2.08. Studies involving DMT (two studies) and multiple psychedelics (three studies) showed mixed results, with DMT studies not showing significant effects on suicidality and studies involving multiple psychedelics showing varying outcomes, some reporting reductions in suicidal ideation and others showing no significant change. Conclusions: The effect of psychedelic therapies on suicide-related outcomes remains inconclusive, highlighting the need for further trials to clarify safety and therapeutic mechanisms.

How Psychedelics Modulate Multiple Memory Mechanisms in Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is a psychiatric disorder with defining abnormalities in memory, and psychedelics may be promising candidates for the treatment of PTSD given their effects on multiple memory systems. Most PTSD and psychedelic research has investigated memory with fear conditioning and extinction. While fruitful, conditioning and extinction provide a limited model of the complexity of PTSD and phenomenology of psychedelics, thereby limiting the refinement of therapies. In this review, we discuss abnormalities in fear conditioning and extinction in PTSD and review 25 studies testing psychedelics on these forms of memory. Perhaps the most reliable effect is that the acute effects of psychedelics can enhance extinction learning, which is impaired in PTSD. However, the post-acute effects may also enhance extinction learning, and the acute effects can also enhance fear conditioning. We then discuss abnormalities in episodic and semantic memory in PTSD and review current knowledge on how psychedelics impact these memory systems. Although PTSD and psychedelics acutely impair the formation of hippocampal-dependent episodic memories, psychedelics may acutely enhance cortical-dependent learning of semantic memories that could facilitate the integration of trauma memories and disrupt maladaptive beliefs. More research is needed on the acute effects of psychedelics on episodic memory consolidation, retrieval, and reconsolidation and post-acute effects of psychedelics on all phases of episodic memory. We conclude by discussing how targeting multiple memory mechanisms could improve upon the current psychedelic therapy paradigm for PTSD, thereby necessitating a greater emphasis on assessing diverse measures of memory in translational PTSD and psychedelic research.

The Epidemiology of Psychedelic Use Among United States Military Veterans

We sought to identify patterns of psychedelic use among United States military veterans, compare demographic variables and perspectives of those who did and did not report use, and characterize benefits and adverse outcomes associated with use. Respondents (N = 426) were recruited to complete an online cross-sectional survey. Approximately one-half (51%) reported using psychedelics. Most did so for healing/treatment (70%) and/or spiritual purposes (48%), and most (85%) reported benefiting from use. Those who used psychedelics reported they would be more likely to use VA services (p < .001, d = 0.64) and to return to the VA for care (p < .001, d = 0.79) if psychedelic therapy was offered. Almost two-thirds (59%) reported adverse outcomes associated with use. Equivalent proportions rated their psychedelic experiences as beneficial among those who did (89%) and did not (81%) report adverse outcomes. Fewer adverse outcomes were associated with being older, using psilocybin, feeling prepared and confident in the reasons for use, being in a comfortable setting, and being able to "trust, let go, and be open" (Rc = 0.77; p < .001). Psychedelics may offer benefits but may also lead to adverse outcomes without proper preparation and support. Future research should examine the utility of psychedelic-based approaches for veteran mental health care.

Ethnoracial inclusion in clinical trials of psychedelics: a systematic review

Background

Prior data indicate limited ethnoracial diversity in studies testing psychedelic-assisted treatments. Regulatory approval for psychedelic treatments may be imminent given growing evidence for safety and efficacy in a variety of psychiatric conditions. Data on racial and ethnic inclusion rates in clinical psychedelic studies since 2018 have not been systematically reported to date. With the publication of multiple new studies in the field, an update to existing ethnoracial inclusion data is needed to inform the state of the science and future directions for research.

Methods

Systematic review of Pubmed/MEDLINE, EMBASE, and Web of Science for studies of any design testing a psychedelic treatment for a psychiatric or substance use disorder published between January 1, 1994 and May 24, 2024. Search terms related to serotonergic psychedelics and MDMA, psychedelic therapies, psychiatric disorders, and substance use disorders were used. References of reviewed studies were screened for inclusion. Studies were rated for quality on a five-point scale ranging from 1 (most rigorous, i.e., properly powered randomized clinical trial) to 5 (least rigorous, e.g., case reports). Separate analyses were performed for two groups of studies, one involving all included studies meeting search criteria, and the other involving only studies from the USA. Rates of inclusion of different ethnoracial groups were calculated between studies published before and after December 31, 2017. Additionally, the proportion of White vs. non-White participants was compared between studies published before and after December 31, 2017. Finally, a nonparametric Mann-Whitney U test was used to compare the relative quality ratings of studies published before and after December 31, 2017.

Findings

787 studies were screened, and 39 studies were included. This included 16 studies (n = 282) from a prior review published in 2018 with an additional 23 studies (n = 1111) that were published after 2017, consisting of 14 randomized controlled studies, 8 open-label studies, and 1 placebo-controlled, within-subject, fixed-order study. In all included studies published after 2017, 85.6% of participants identified as non-Hispanic White, 3.1% as Black, 6.8% as Latinx/Hispanic, 3.6% as Asian, 1.2% as Indigenous, 3.5% as mixed race, 1.4% as other, Pooled data from all included studies (n = 1393) found 85.0% of participants identified as non-Hispanic White, 2.9% as Black, 5.9% as Latinx/Hispanic, 3.2% as Asian, 1.9% as Indigenous, 3.7% as mixed race, 1.4% as other. In studies conducted in the USA (n = 1074), 908 (84.5%) of participants identified as White, 36 (3.4%) as Black, 80 (7.4%) as Latinx/Hispanic, 43 (4.0%) as Asian, 15 (1.4%) as Indigenous, 40 (3.7%) as Mixed, and 9 (0.8%) as Other. Differences in inclusion rates were found when comparing studies published before and after December 31, 2017 for all included studies and all studies conducted in the USA. The proportion of White to non-White participants was found to have decreased in studies conducted in the USA over the same period, but not for all included studies.

Interpretation

Underrepresentation of ethnoracial minoritized populations persists in studies examining psychedelic therapies, despite growing calls for diversity. Non-Hispanic White participants remain an over-represented majority by a large margin, though, there were greater proportions of ethnic minoritized populations included in studies since 2018, particularly in studies conducted in the USA. This indicates progress towards equity in psychedelic research, though much work is needed to inform the safety and efficacy of psychedelic treatments in the general population.

Funding

There was no funding source for this study.

Psychedelic Therapy: A Primer for Primary Care Clinicians-Ibogaine

BACKGROUND

Ibogaine is a plant-derived alkaloid that has been used for thousands of years in rites of passage and spiritual ceremonies in West-Central Africa. In the West, it has primarily been used and studied for its anti-addictive properties and more recently for other neuropsychiatric indications, including post-traumatic stress disorder, depression, anxiety, and traumatic brain injury.

AREAS OF UNCERTAINTY

Ibogaine requires careful patient screening and monitoring because of significant safety issues. There is potential for cardiotoxicity (prolonged QT interval); without rigorous screening, fatal arrhythmias may occur. However, preliminary research suggests that co-administration of ibogaine with magnesium may mitigate cardiotoxicity. Additionally, ibogaine may have dangerous interactions with opiates, so patients who receive ibogaine treatment for opioid use disorder must withdraw from long-acting opioids. Other potential concerning effects of ibogaine include rare incidences of mania or psychosis. Anticipated transient effects during ibogaine treatment can include ataxia, tremors, and gastrointestinal symptoms.

THERAPEUTIC ADVANCES

Robust effects after a single treatment with ibogaine have been reported. In open-label and randomized controlled trials (RCTs), ibogaine reduces heroin and opioid cravings by upwards of 50%, up to 24 weeks after the treatment. An observational study of 30 Special Operations Forces veterans with mild traumatic brain injury reported that 86% were in remission from post-traumatic stress disorder, 83% from depression, and 83% from anxiety, one month after a single-dose ibogaine treatment.

LIMITATIONS

Although there are several observational and open-label studies, there is only a single double-blind, placebo-controlled RCT on ibogaine. More RCTs with large sample sizes must be conducted to support ibogaine's safety and efficacy.

CONCLUSIONS

Given the promising preliminary findings, ibogaine could potentially fill a much-needed gap in treatments for challenging conditions, including opioid dependence. Ibogaine's remarkable effects in traditionally treatment-resistant, combat-exposed individuals hints at its potential in broader populations with physical and psychological trauma.