Findings from contemporary clinical trials suggest that psychedelics are generally safe and may be effective in the treatment of various psychiatric disorders. However, less is known about the risks associated with psychedelic use outside of medically supervised contexts, particularly in populations that are typically excluded from participation in clinical trials.

Using a preregistered longitudinal observational research design with a purposive sample of US residents between 18 and 50 years old (N=21,990), we investigated associations between self-reported naturalistic psychedelic use and psychotic and manic symptoms, with emphasis on those with psychiatric histories of schizophrenia or bipolar I disorder.

The follow-up survey was completed by 12,345 participants (56% retention), with 505 participants reporting psychedelic use during the 2-month study period. In covariate-adjusted regression models, psychedelic use during the study period was associated with increases in the severity of psychotic and manic symptoms. However, such increases were only observed for those who reported psychedelic use in an illegal context. While increases in the severity of psychotic symptoms appeared to depend on the frequency of use and the intensity of challenging psychedelic experiences, increases in the severity of manic symptoms appeared to be moderated by a personal history of schizophrenia or bipolar I disorder and the subjective experience of insight during a psychedelic experience.

The findings suggest that naturalistic psychedelic use specifically in illegal contexts may lead to increases in the severity of psychotic and manic symptoms. Such increases may depend on the frequency of use, the acute subjective psychedelic experience, and psychiatric history.

Understanding variations in knowledge and attitudes of psychiatrists to psilocybin therapy is important for the collective discourse about the potential impact on clinical practice and public health in Ireland.

A 28-item questionnaire was designed based on previous studies and distributed to psychiatrists in Ireland via online mailing lists and at in-person academic events.

151 psychiatrists completed the questionnaire (73.3% were under 40 years of age, 76.0% were trainees, and 49.0% were female). In the total sample, 81.5% agreed that psilocybin therapy shows promise in the treatment of psychiatric disorders and 86.8% supported funding research, 86.8% would be willing to refer a patient if it was licensed and indicated, and 78.1% would consider the treatment for themselves, if indicated. Conversely, 6.6% agreed that psilocybin therapy was unsafe even under medical supervision, and 21.9% thought it was potentially addictive. 15.9% of the total sample reported at least one concern including, lack of robust evidence, long-term effectiveness, superiority to current interventions, potential harmful effects, cost and accessibility, and impartiality. Less than half of respondents felt knowledgeable (40.0%) and 9.9% felt adequately prepared to participate in psilocybin therapy. Consultant psychiatrists trended towards less optimism for a potential role in bipolar depression and emotionally unstable personality disorder compared to trainee psychiatrists.

Overall psychiatrists in Ireland held positive attitudes towards psilocybin therapy. However, there was a lack of knowledge evident. Addressing the knowledge gap and aligning with the best available evidence will be key if psychedelic therapy is to prevail in a clinical setting.

Previous research has proposed that there may be potential synergies between psychedelic and meditation interventions, but there are still knowledge gaps that merit further investigation.

Using a longitudinal observational research design with samples representative of the US and UK adult population with regard to sex, age, and ethnicity (N = 9732), we investigated potential associations between self-reported psychedelic use and meditation practice.

The follow-up survey was completed by 7667 respondents (79% retention rate), with 100 respondents reporting psychedelic use during the 2-month study period (1.3% of follow-up respondents). In covariate-adjusted regression models, psychedelic use during the study period was associated with greater increases in the number of days of mindfulness meditation practice in the past week (B = 0.40, p = 0.004). Among those who reported psychedelic use during the study period, covariate-adjusted regression models revealed that the subjective experience of insight during respondents' most intense psychedelic experience in that period was also associated with greater increases in the number of days of mindfulness and loving-kindness or compassion meditation practice in the past week (B = 0.42, p = 0.021; B = 0.38, p = 0.017). Notably, more days of loving-kindness or compassion meditation practice in the past week at baseline was associated with less severe subjective feelings of death or dying during respondents' most intense psychedelic experience in the study period (B = −0.29, p = 0.037).

Psychedelic use might lead to greater engagement with meditation practices such as mindfulness meditation, while meditation practices such as loving-kindness or compassion medication might buffer against certain challenging experiences associated with psychedelic use.