Journal of Psychopharmacology
June 26, 2026
Flavia Giaffone de Paiva Ferreira, João Ariel Bonar Fernandes, Renato Filev et al.
A scoping review categorized psychosocial protocols used in psychedelic research for mental health treatment. Seven categories were defined, reflecting distinct emphases on the substance, participant, research team, and sociocultural context. Although limited reporting and heterogeneity remain methodological challenges, the proposed parameters suggest a shared language to describe, compare, and examine psychosocial protocols across studies, reducing conceptual uncertainty. The review may facilitate research decision-making and support structured, replicable study designs while allowing flexibility for individualized and culturally responsive care. Explicitly defining the intended purpose of psychosocial protocols could improve transparent reporting and evaluation.
Journal of Psychopharmacology
June 23, 2026
Lenka Seillier, Alexandre Seillier, Morgan A. Zvolska et al.
Psilocybin produces rapid and sustained antidepressant-like effects in rats, as measured by reduced immobility and increased climbing in the forced swim test. Blocking the 5-HT2B receptor with the antagonist RS-127445 dose-dependently reversed these behavioral effects, indicating that 5-HT2B receptors are necessary for psilocybin's antidepressant-like activity. However, the same antagonist did not affect psilocybin-induced head-twitch responses, a proxy for psychedelic effects, suggesting that the antidepressant-like and psychedelic effects of psilocybin can be dissociated via different serotonin receptor subtypes.
Journal of Psychopharmacology
May 12, 2026
Pravesh Sharma, Jared Kendrick, Jennifer Schram et al.
A review of human studies on ibogaine and its metabolite noribogaine found only three randomized controlled trials. In one pilot study, a single 1800 mg dose of ibogaine reduced cocaine craving versus placebo over up to 24 weeks in 20 adults. Noribogaine doses of 3-60 mg were safe in 36 healthy volunteers. In 27 opioid-dependent patients, noribogaine 60-180 mg caused dose-dependent QTc prolongation with non-significant reductions in withdrawal symptoms. Adverse effects include neurologic, psychiatric, and cardiac events, and fatalities have occurred with comorbidities. Microdosing protocols lack standardized definitions and are supported only by preliminary observational data. The authors conclude that clinical use cannot be recommended without larger, well-controlled trials due to cardiotoxicity and a narrow therapeutic margin.
Journal of Psychopharmacology
April 12, 2026
L. M. Wallace, Andrea Bujor, Gustavo Sudre et al.
A systematic review and meta-analysis of studies from 1960 to 2024 found that the psychedelic agent DMT produced a large overall effect on reducing substance abuse (g = 0.94). Effects were larger for drug use (g = 1.35) than for alcohol use (g = 0.65). Studies that included psychotherapy showed significantly greater effects (g = 1.38) than those without (g = 0.60). However, the included studies had high risk of bias and high heterogeneity, so the findings should be considered preliminary rather than proof of established efficacy.
Journal of Psychopharmacology
March 9, 2026
Alicia Cohorst, Petri Kajonius
A meta-analysis and systematic review found that psychedelic substances are associated with moderate-to-large reductions in death anxiety, with a significant overall effect size (Cohen's d = 0.70). Stronger effects were observed in clinically controlled settings than in the general population, and mystical experiences were positively linked to these reductions. The qualitative review identified themes of ego dissolution, emotional catharsis, and living in the present moment. The findings suggest psychedelic-assisted interventions may be effective for reducing death anxiety, especially in end-of-life care, though limitations include a small number of studies, potential publication bias, and high heterogeneity in outcome measurement.
Journal of Psychopharmacology
February 27, 2026
Claire T. Roberts, Mathieu Seynaeve, Anna O. Ermakova et al.
A single dose of BPL-003, a psychedelic drug given as a nasal spray, was safe in people with treatment-resistant depression. Depression scores dropped quickly and stayed lower for 12 weeks, suggesting the drug may help this hard-to-treat condition. Larger controlled trials are needed.
Journal of Psychopharmacology
December 4, 2025
Natan Silva-Costa, Jéssica Andrade Pessoa, Kátia Cristina Andrade et al.
Ayahuasca produces profound changes in perception, cognition, and emotion, including mystical experiences and altered mind-wandering, while decreasing global alpha brain oscillations and increasing frontomedial delta and right posterior theta and beta. Lower theta during the experience is linked to stronger mystical experiences, and higher alpha is associated with less thought about nothing. Baseline brain activity before taking ayahuasca can predict some subjective effects: lower baseline theta predicts stronger bodily awareness and interoception, and lower baseline beta predicts greater positive emotionality.
Journal of Psychopharmacology
April 17, 2025
Artur Pałasz, Marta Pukowiec, Katarzyna Bogus et al.
A single high dose of psilocybin (10 mg/kg) increased the gene expression of most noncanonical neuropeptides in the hypothalamus of male rats, while decreasing expression of neuromedin U. Psilocybin also raised expression of serotonin receptors 5-HT1A, 5-HT2A, and 5-HT2B, but not 5-HT2C. Ketamine had a more limited effect, increasing only NUCB2, GPR173, and POMC transcripts. These findings suggest psychedelics may alter neuropeptide signaling and serotonin transmission in the hypothalamus, contributing to understanding their brain actions.
Journal of Psychopharmacology
July 1, 2023
Emma Morton, Kimberly Sakai, Amir Ashtari et al.
No Summary
Journal of Psychopharmacology
July 14, 2019
Livia Ng, Luca Pani, Anaïs Soula et al.
Claims about the positive effects of microdosing psychedelics on mood and cognition have entered public discussion, but scientific studies are scarce and no consensus on what microdosing means exists. This critique identifies questions future research must answer and offers guidelines, focusing on psilocybin due to its potential clinical approval and short-lasting effects. While anecdotal reports emphasize benefits, the paper concludes that future studies should also investigate potential risks of repeated low-dose administrations. Preclinical and clinical research examining biological measures like heart rate and receptor turnover, as well as cognitive parameters such as memory and attention, is needed to uncover possible negative consequences.
Journal of Psychopharmacology
November 3, 2025
P. di Ciano, B. Le Foll, S. Zhao et al.
Older adults aged 65–78 who smoked their preferred legal cannabis with an average THC content of 18.7% showed decreased performance on the trail making test (versions A and B) 60 minutes after smoking, compared to when they were sober. However, the percentage of words retained in a verbal free recall test was significantly higher after cannabis, apparently due to a reversal in performance decrement. Smoked cannabis produced robust subjective drug effects. Correlations between blood THC levels and cognitive performance at 60 and 210 minutes were unclear. The findings suggest that older adults who use cannabis may show decrements on only some cognitive tests, along with marked changes in subjective experience.
Journal of Psychopharmacology
August 26, 2025
Emma S. J. Robinson
Psychiatric disorders such as anxiety and major depressive disorder are difficult to study in non-human animals because they are diagnosed through clinical interviews and self-reported symptoms. Despite over 70 years of research, how antidepressants affect mood remains unknown. With renewed interest in psychedelic treatments, translational methods are needed to study underlying mechanisms and predict clinical effects. Human studies have limited resolution and mechanistic depth, so animal studies are important for understanding how psychedelics alter behavior and for drug development. Their value depends on using clinically relevant methods. This perspective article considers whether 'behavioral biomarkers' translated to animal tasks could provide this approach.
Journal of Psychopharmacology
May 25, 2021
Ashley M. Schnakenberg Martin, Dae-Jin Kim, Sharlene D. Newman et al.
Regular cannabis users show altered resting-state functional connectivity between the cerebellum and the cerebral cortex compared with non-using peers. The anterior cerebellum is hyperconnected to the posterior cingulate cortex, while most other cerebellar regions are hypoconnected to the cortex. These connectivity changes may affect behavior and cognition. No associations were found between cannabis use features—such as age of initiation or lifetime use—and the observed connectivity differences.
Journal of Psychopharmacology
February 1, 2020
A. Winstock, J. Ferris
Nitrous oxide use, both clinical and recreational, can cause peripheral neuropathy by inactivating a vitamin B12-dependent enzyme. Among over 16,000 past-year users surveyed across three years, 3.3% reported persistent numbness or tingling in hands or feet. The risk was very low for infrequent users but showed a strong dose-response relationship: the probability of paraesthesia rose from about 0.018 for 1–2 doses per session to about 0.085 for 100 doses per session. Age and gender also influenced the association. Heavy users face a dose-dependent risk of serious neurological harm, while occasional users are not at risk.
Journal of Psychopharmacology
July 26, 2019
C. Roberts, G. Jager, P. Christiansen et al.
Cannabis intoxication, commonly known as giving users 'the munchies,' increases appetite and enhances the enjoyment of food by activating the endocannabinoid system. An online survey of frequent cannabis users developed and validated the Cannabinoid Eating Experience Questionnaire (CEEQ) to measure psychological changes underlying these effects. Analysis of responses from 591 English-speaking and 163 Dutch-speaking participants identified two key factors: hedonic enjoyment (altered sensory aspects of eating) and appetitive motivation (factors that instigate eating). Both subscales showed high internal reliability and good test-retest reliability over two weeks. The findings confirm that cannabis primarily affects motivational factors that initiate eating and hedonic factors that sustain it.
Journal of Psychopharmacology
January 1, 1998
D.V. Gauvin, S.A. Vanecek, T.J. Baird et al.
Rats were trained to distinguish two over-the-counter drug mixtures—dextromethorphan plus diphenhydramine and dextromethorphan plus ephedrine—from a placebo. The mixtures were not perceived as entirely new substances; instead, their individual components contributed to the rats' discrimination. Stimulant drugs like cocaine and amphetamine fully substituted for both mixtures, while pentobarbital did not. The findings suggest these common drug combinations have potential for abuse and caution against their use in children.