Psychiatry research
May 1, 2024
B Romeo, E Kervadec, B Fauvel et al.
48 citations
Psychedelic-assisted psychotherapies show promise for psychiatric disorders. A systematic review and meta-analysis of 30 studies found that over more than 1000 administrations, only nine serious adverse events occurred (one during the acute phase, eight post-acute). No suicide attempts happened during the acute phase, but three participants engaged in self-harm post-acute. Psychedelics increased risk of elevated heart rate, systolic and diastolic blood pressure across all dose ranges, and nausea during the acute phase. Common side effects included headaches, anxiety, and decreased concentration or appetite. The analysis indicates that psychedelics are well-tolerated with a low risk of serious adverse events in controlled settings with appropriate inclusion criteria.
Neuroscience and biobehavioral reviews
May 1, 2025
B Romeo, E Kervadec, B Fauvel et al.
36 citations
A meta-analysis of studies on psychedelic-assisted therapies found a significant positive correlation between the intensity of mystical experiences and clinical improvement across all diagnoses (r = .33). The association was stronger for mood disorders (r = .41) than for addictions (r = .19), and greater in protocol-based clinical settings (r = .50) than in naturalistic use (r = .14). Prospective designs showed stronger correlations (r = .43) than retrospective designs (r = .14). The intensity of psychedelic experiences is reliably associated with therapeutic outcomes, especially for mood disorders, and controlled environments and therapeutic support strengthen this relationship.
L'Encephale
August 1, 2021
L Berkovitch, B Roméo, L Karila et al.
25 citations
A systematic review of 25 studies found that psychedelics (psilocybin, ayahuasca, and LSD) produce a quick and substantial reduction in symptoms of anxiety, depression, and addiction that lasts for several months, sometimes after a single dose. Studies included randomized controlled trials, open-label trials, and long-term follow-ups, with no severe adverse events reported. However, most studies were descriptive or open-label with small sample sizes. The evidence suggests psychedelics are promising treatments that are well tolerated, but effects need confirmation in larger trials and comparison with standard care.
Journal of psychoactive drugs
January 1, 2023
B Romeo, B Fauvel, S Dejean et al.
14 citations
A retrospective online survey of 173 smokers who had a psychedelic experience found that average cigarettes per day and the proportion with high tobacco dependency dropped significantly afterward. Participants who reduced or quit smoking reported more intense mystical experiences during the session and lower psychological flexibility before it. Increased psychological flexibility after the session and personal motives for taking the psychedelic were positive predictors of smoking reduction or cessation. The findings suggest that a naturalistic psychedelic experience can be linked to reduced tobacco use, with the intensity of the mystical experience, personal motives, and gains in psychological flexibility playing key roles.
Progress in neuro-psychopharmacology & biological psychiatry
March 20, 2025
B Romeo, E Kervadec, B Fauvel et al.
5 citations
The intensity of mystical experiences during naturalistic psychedelic use is associated with several factors, including the type of substance, dosage, and the user's intentions. Analyzing data from 1657 participants across four retrospective surveys, higher mystical experience questionnaire scores were linked to spiritual, therapeutic, or self-exploration motives (versus recreational), use of ayahuasca or LSD (versus psilocybin), higher subjective doses, more sessions, longer time since the experience, and no concurrent alcohol use. Concomitant alcohol use was associated with less intense experiences, highlighting the need to screen for substance use in research.
Journal of psychoactive drugs
July 3, 2024
B Romeo, E Kervadec, B Fauvel et al.
5 citations
Among 152 cannabis users who had a significant past psychedelic experience, an online retrospective survey found that after the experience there was a sustained reduction in cannabis use disorder scores, frequency of use, and daily intoxication duration. The reduction in cannabis use during the first month was linked to the intensity of the mystical experience. Participants also reported lasting improvement in psychological flexibility, which was correlated with mystical experience intensity. The findings suggest naturalistic psychedelic experiences may lead to decreased cannabis use, possibly through increased psychological flexibility and mystical experience intensity.
Progress in neuro-psychopharmacology & biological psychiatry
January 23, 2026
B Romeo, E Kervadec, B Fauvel et al.
1 citation
The intensity of a psychedelic experience, which is linked to clinical benefits, depends on multiple factors. In an online survey of 804 people, stronger altered states of consciousness were reported when the experience was intended for spiritual, therapeutic, or self-exploratory purposes rather than recreation; when dissociative or serotonergic psychedelics were used instead of entactogens; and with moderate to very high doses compared to very low doses. Age and gender also played a role. The findings suggest that experiential intensity arises from a combination of pharmacological, personal, and contextual elements, and that similarities with mystical experiences may point to a shared neurobiological sensitivity rather than a unique category of experience.
Journal of psychoactive drugs
November 4, 2024
A Bezo, B Roméo, Y Le Strat et al.
1 citation
Physicians in France perceive the use of psychedelics as carrying notable risks. In a survey of 407 clinicians, average ratings on 1–5 Likert scales were 3.05 for general risk, 2.68 for self-harm risk, 2.47 for aggression risk, 2.71 for addictive risk, 2.76 for psychiatric disorder risk, and 2.11 for somatic disorder risk. Younger physicians were more likely to see therapeutic potential, while general practitioners were less likely than specialists to consider psychedelics a treatment. Clinicians who viewed psychedelics as having therapeutic potential associated them with lower risks.
Journal of psychoactive drugs
April 25, 2025
B Romeo, E Kervadec, B Fauvel et al.
A retrospective online survey of French individuals who had a significant psychedelic experience found that the intensity of the mystical experience was positively correlated with improvements in psychological flexibility, especially one month after the experience and during the six months before the survey. Key predictors of changes in psychological flexibility included baseline flexibility scores, the intensity of the mystical experience, and frequent psychedelic use. The findings suggest that the intensity of the mystical experience and baseline psychological flexibility may be key factors influencing changes in psychological flexibility after psychedelic use, indicating potential therapeutic value.