Behaviour Research and Therapy
August 10, 2026
Otto Simonsson, Christian A. Webb, Mini Ruiz et al.
Despite decades of meditation research, there is a lack of preregistered and well-powered studies that investigate the effects of brief meditation practices on subjective wellbeing and use data-driven approaches to predict response to these interventions. Using representative samples of the US and UK adult populations with regards to age, sex, and ethnicity (N = 5049), we conducted a...
Psychedelic Medicine
June 22, 2026
Otto Simonsson, Peter S. Hendricks, Walter Osika et al.
Background: Previous research indicates that psychedelics may produce outcomes that are dependent on the immediate context. Recent scholarship hypothesizes that such outcomes may also depend on the broader sociocultural context, but empirical data are lacking. Methods: Using a longitudinal observational research design with a large sample of US adults ( N = 21,990) followed during a 2-month...
Research Square
May 19, 2026
Sunjuri Sun, Claudia Hanson, Peter S. Hendricks et al.
As the cultural, scientific, and legal landscape surrounding psychedelics continues to shift toward greater access and acceptability, it is likely that increasing numbers of women of reproductive age may be exposed to these substances. Despite this, the evidence on antenatal exposure has not been systematically reviewed. To synthesize the human literature on child and maternal outcomes...
Journal of psychopharmacology (Oxford, England)
May 1, 2026
Otto Simonsson, Sunjuri Sun, Laura W. Wesseldijk et al.
While psychedelics have shown initial promise in the treatment of migraine, experimental studies have relied on small and homogenous samples, which limit the reliability and generalizability of findings. These limitations underscore the complementary value of other research designs that leverage larger and more representative samples. This cross-sectional study included three cohorts of twins...
Int J Drug Policy
December 13, 2025
Michelle Olofsson, Walter Osika, Simon B. Goldberg et al.
2 citations
BACKGROUND: Naturalistic psychedelic use can result in a range of difficulties that impair social, occupational, and other important areas of functioning. Yet, the prevalence, phenomenology, and etiology of these outcomes remain poorly understood. Recent qualitative research has shown that individuals with long-term difficulties after psychedelic use sometimes attribute their challenges to...
Journal of Affective Disorders
July 9, 2025
Otto Simonsson, Peter S. Hendricks, Caroline M. Swords et al.
8 citations
While growing evidence suggests that psychedelic-assisted therapy may have antidepressant effects in certain populations, little is known about the effects of psychedelic use on depressive symptoms in non-clinical, naturalistic settings. This observational cohort study included a large sample of US residents (18-50 years old) and longitudinally evaluated the relationships between naturalistic...
Psychopharmacology
July 1, 2025
Otto Simonsson, Simon B. Goldberg, Richard Chambers et al.
33 citations
Research on psychedelics has recently shown promising results in the treatment of various psychiatric disorders, but relatively little remains known about the psychiatric risks associated with naturalistic use of psychedelics. The objective of the current study was to investigate associations between naturalistic psychedelic use and psychiatric risks. Using a sample representative of the US...
Psychol Med
March 31, 2025
Otto Simonsson, Simon B. Goldberg, Walter Osika et al.
16 citations
BACKGROUND: 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. METHODS:...
J Psychiatr Res
March 17, 2025
Otto Simonsson, Sankalp Chaturvedi, Peter S. Hendricks et al.
2 citations
Previous research has investigated associations between psychedelic experiences and meditation practice, but knowledge gaps remain. Using a longitudinal research design with a sample of US residents between 18 and 50 years old (N = 13,012), we investigated associations between psychedelic-related and meditation-related variables. The follow-up survey was completed by 7484 respondents, of whom...
Psychological Medicine
April 1, 2024
Otto Simonsson, Walter Osika, Cecilia U.D. Stenfors et al.
15 citations
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...
JAMA Psychiatry
March 13, 2024
Otto Simonsson, Miriam A. Mosing, Walter Osika et al.
41 citations
Importance While psychedelic-assisted therapy has shown promise in the treatment of certain psychiatric disorders, little is known about the potential risk of psychotic or manic symptoms following naturalistic psychedelic use, especially among adolescents. Objective To investigate associations between naturalistic psychedelic use and self-reported psychotic or manic symptoms in adolescents...
Journal of Affective Disorders
January 26, 2024
Ludwig Honk, Cecilia U.D. Stenfors, Simon B. Goldberg et al.
41 citations
It has long been speculated that psychedelic use could provoke the onset of psychosis, but there is little evidence to support this conjecture. Using a longitudinal research design with samples representative of the US and UK adult populations with regard to sex, age, and ethnicity (n = 9732), we investigated associations between psychedelic use and change in the number of psychotic symptoms...
Journal of psychopharmacology (Oxford, England)
2024
Otto Simonsson, Peter S. Hendricks, Cecilia Ud Stenfors et al.
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. To investigate longitudinal associations between...
Scientific Reports
September 30, 2023
Alexander V. Lebedev, Kasim Acar, Otilia Horntvedt et al.
9 citations
Previous research has suggested that classical psychedelics can foster significant and enduring changes in personality traits and subjective wellbeing. Despite the lack of evidence for adverse effects on mental health stemming from psychedelic use, concerns persist regarding the capacity of these substances to modulate information processing and attitudes towards factual data. The aim of the...
Journal of Affective Disorders
April 1, 2023
Otto Simonsson, Peter S. Hendricks, Richard Chambers et al.
124 citations
Previous studies have investigated challenging, difficult, or distressing classic psychedelic experiences, but little is known about the prevalence and associations of such experiences. Using nationally representative data of the US adult population (N = 2822), this study examined the prevalence and associations of challenging, difficult, or distressing experiences using classic psychedelics,...
Mindfulness
April 1, 2023
Charlotta Simonsson, Richard Chambers, Peter S. Hendricks et al.
15 citations
Previous research has investigated potential synergies between classic psychedelics and meditation practice, but relatively little remains known about the relationship between classic psychedelic experiences and engagement with meditation practice.The purpose of this study was to investigate associations between classic psychedelic experiences and engagement with two popular types of...
Frontiers in Psychology
2023
Otto Simonsson, Cecilia U.D. Stenfors, Simon B. Goldberg et al.
4 citations
Previous research suggests that mindfulness meditation and psychedelic substances show promise as mental health interventions, but relatively little remains known about their potential impact on leadership outcomes. This study aimed to investigate if and how mindfulness meditation and psychedelic use may impact leadership among respondents with a management position as their primary role at...
Drug and Alcohol Dependence
October 1, 2022
Otto Simonsson, Simon B. Goldberg, Richard Chambers et al.
16 citations
Previous studies have reported links between classic psychedelic use and seizures, but little remains known about prevalence and potential risk factors of classic psychedelic-related seizures. Using a sample representative of the US adult population with regard to sex, age, and ethnicity (N = 2822), this study examined the prevalence and potential risk factors of classic psychedelic-related...
International Journal of Environmental Research and Public Health
July 1, 2022
Elin Pöllänen, Walter Osika, Otto Simonsson et al.
12 citations
Previous research has found associations between classic psychedelic use and nature-relatedness, but the link between classic psychedelic use and human–animal relations remains largely unexplored. Using data representative of the US adult population, with regard to age, sex and ethnicity (N = 2822), this pre-registered study assessed lifetime classic psychedelic use, ego dissolution during...
Therapeutic Advances in Psychopharmacology
2022
Otto Simonsson, Peter S. Hendricks, Richard Chambers et al.
26 citations
Preliminary evidence suggests that classic psychedelics may be effective in the treatment of some psychiatric disorders, yet little remains known about their effects on health behavior and physical health. The purpose of this study was to investigate associations of lifetime classic psychedelic use and psychological insight during one's most insightful classic psychedelic experience with health...
Scientific Reports
July 13, 2021
Otto Simonsson, Walter Osika, Robin Carhart-Harris et al.
54 citations
Abstract The objective of the current study was to investigate the associations between lifetime classic psychedelic use and cardiometabolic diseases. Using data from the National Survey on Drug Use and Health (2005–2014), the present study examined the associations between lifetime classic psychedelic use and two types of cardiometabolic disease: heart disease and diabetes. Respondents who...
Hypertension
March 8, 2021
Otto Simonsson, Peter S. Hendricks, Robin Carhart-Harris et al.
36 citations
Using data from the National Survey on Drug Use and Health (2005–2014), weighted to be representative of the US adult population, the present study investigated the association between lifetime classic psychedelic use and hypertension in the past year among adults in the United States. The results showed that respondents who reported having used a classic psychedelic at least once in their...