Assessing the risk of symptom worsening in psilocybin-assisted therapy for depression: A systematic review and individual participant data meta-analysis

Giving Consent to the Ineffable

A psychedelic renaissance is currently taking place in mental healthcare. The number of psychedelic-assisted therapy trials is growing steadily, and some countries already grant psychiatrists special permission to use psychedelics in non-research contexts under certain conditions. These clinical advances must be accompanied by ethical inquiry. One pressing ethical question involves whether patients can even give informed consent to psychedelic-assisted therapy: the treatment's transformative nature seems to block its assessment, suggesting that patients are unable to understand what undergoing psychedelic-assisted therapy actually means for them and whether it aligns with their values. The present paper argues that patients often have sufficient knowledge to give informed consent because they know that they want to change their negative status quo and that psychedelic-assisted therapy offers an effective way to do so. Accordingly, patients can understand what the transformative nature of psychedelic-assisted therapy means for them and a make a value-aligned choice even if they are unable to anticipate the manifestation of a psychedelic experience.

Psilocybin-enhanced fear extinction linked to bidirectional modulation of cortical ensembles

The serotonin 2 receptor (5HT2R) agonist psilocybin has demonstrated rapid and long-lasting efficacy across neuropsychiatric disorders characterized by cognitive inflexibility. Psilocybin may accomplish this by inducing rapid and stable dendritic plasticity. However, the impact of psilocybin on patterns of neural activity underlying sustained changes in cognitive and behavioral flexibility has not been characterized. To test the hypothesis that psilocybin enhances behavioral flexibility by rapidly and persistently altering activity in cortical neural ensembles, we performed longitudinal single-cell calcium imaging in the retrosplenial cortex across a five-day trace fear learning and extinction assay. Leveraging tensor component analysis to identify neurons that modulate activity on multiple temporal scales, we found that a single-dose of psilocybin induced cortical ensemble turnover between fear learning and extinction days while oppositely modulating activity in fear- and extinction-active neurons. The extent of suppression of fear-active neurons and recruitment of extinction-active neurons were both predictive of psilocybin-enhanced fear extinction. These results both align with hypotheses that psilocybin enhances behavioral flexibility by recruiting new populations of neurons and introduce a new mechanism involving the suppression of fear-active populations in the retrosplenial cortex.

Longitudinal associations between psychedelic use and unusual visual experiences in the United States and the United Kingdom

BACKGROUND

Whereas findings from case reports and cross-sectional studies suggest that naturalistic psychedelic use may be associated with unusual visual experiences that occur after the acute pharmacological effects have subsided, such findings need to be replicated in longitudinal studies to better understand potential cause-and-effect relationships.

AIMS

To investigate longitudinal associations between naturalistic psychedelic use and unusual visual experiences.

METHODS

Using a longitudinal observational research design with samples representative of the US and UK adult populations with regard to sex, age, and ethnicity (N = 9732), we investigated the relationship between psychedelic use during the 2-month study period and changes in past-week unusual visual experiences.

RESULTS

The follow-up survey was completed by 79% of respondents (n = 7667), with 100 respondents reporting psychedelic use during the 2-month study period (1.3% of those who responded at follow-up). In covariate-adjusted regression models, the results showed that, as hypothesized, psychedelic use during the 2-month study period was associated with greater increases in unusual visual experiences. Notably, there was an interaction between lifetime psychedelic use and psychedelic use during the study period on unusual visual experiences such that those who used psychedelics for the first time reported greater increases in unusual visual experiences.

CONCLUSIONS

Psychedelic use may elicit unusual visual experiences that occur after the acute pharmacological effects have subsided, especially among those who have not used psychedelics previously. Future longitudinal studies are warranted to further elucidate these relationships.

Small-Molecule Heterocyclic Compounds: Gq-Biased Agonists for the 5-HT2A Receptor in Neuropsychiatric Treatment

Addressing the significant challenges of treating depression, anxiety, and substance abuse, this Patent Highlight explores the development of innovative small-molecule heterocyclic compounds as Gq-biased agonists of the 5-HT2A receptor. Unlike traditional treatments, these compounds selectively activate 5-HT2A-mediated Gq signaling, excluding related receptors like 5-HT2B and 5-HT2C. This selectivity suggests a more targeted and efficient therapeutic approach. The discovery of these compounds could herald a new era in neuropsychiatric treatment, promising safer, faster, and more effective interventions. Further research will illuminate their potential and applicability in clinical settings.