Annals of Internal Medicine
October 1, 2025
Thanitsara Rittiphairoj, Louis Leslie, Jean-Pierre Oberste et al.
12 citations
High-concentration THC cannabis products are consistently linked to worse mental health outcomes, especially psychosis or schizophrenia and cannabis use disorder. Among 99 studies (over 221,000 participants), 70% of non-therapeutic studies found unfavorable associations with psychosis or schizophrenia, and 75% found unfavorable associations with cannabis use disorder. For anxiety and depression, about half of non-therapeutic studies reported unfavorable associations, particularly in healthy populations. Some therapeutic studies suggested benefits for anxiety (47%) and depression (48%), but these findings were low-quality and inconsistent. More than 95% of the studies had moderate or high risk of bias.
JAMA Psychiatry
November 5, 2025
Kent E. Hutchison, Judith Hooper, Hollis C Karoly
10 citations
Psilocybin mushroom use has sharply increased in the US, particularly among adults aged 19 to 50 years, with more than 7 million individuals reporting use in the past year. This trend has coincided with a substantial increase in poison control center calls related to psychedelics. Testing data from decriminalized regions indicate more than 20-fold variability in psilocybin potency and inconsistent levels of minor tryptamines across mushroom strains. Clinical trial data on synthetic psilocybin do not generalize to public use due to strict participant selection and controlled environments. Co-use with cannabis is common and may increase the risk of adverse events. The expanding use of unregulated psilocybin mushrooms, combined with high variability in composition and common co-use with other substances, raises urgent public health concerns.
Frontiers in Psychology
May 15, 2025
Jake Hooper, Emily L Gyongyosi, Kent E. Hutchison et al.
5 citations
Aesthetic qualities of psychedelic experiences are linked to better psychological outcomes, including greater emotional breakthroughs, psychological insight, behavioral change, and mystical experiences, while also being associated with less fear and paranoia. In a survey of 96 people who used classic psychedelics in the past year, aesthetic experience predicted improvements in depression, anxiety, and quality of life independently of age, gender, or mystical experience. The findings suggest that the aesthetic environment in psychedelic-assisted therapy may actively contribute to therapeutic benefits rather than being merely perceptual enhancements.
Frontiers in Psychology
September 15, 2025
Judith Hooper, Jarrod M. Ellingson, Kent E. Hutchison
2 citations
Aesthetic experiences under psychedelics are vivid and meaningful but poorly measured. A new questionnaire, the Psychedelic Aesthetic Experience Questionnaire (PAEQ), was refined and validated in 365 past-year psilocybin users who completed an online survey. Factor analysis revealed four dimensions: sensory, affective, semantic, and flow. The scale showed high internal consistency (α = 0.90) and strong correlations with existing measures of mystical experience, emotional breakthrough, and psychological insight. PAEQ scores modestly predicted improvements in sleep, pain, substance use, anxiety, depression, and quality of life after psychedelic use. The PAEQ offers a psychometrically sound tool for capturing aesthetic engagement during psychedelic experiences.
May 22, 2025
Judith Hooper, Sarah Williams, Raeghan L. Mueller et al.
2 citations
preprint
Age and cannabis co-use influence the acute effects and therapeutic outcomes of psilocybin. In a cross-sectional study of 365 current psilocybin users aged 18–77, younger participants reported more adverse experiences, while older adults had milder subjective effects. However, age did not significantly affect mystical experiences, psychological insight, or psychological outcomes. Polysubstance use patterns varied by age, with younger adults more likely to co-use nicotine. Cannabis co-use was associated with greater improvements in quality of life, anxiety, depression, and alcohol abuse, suggesting potential synergies between psilocybin and THC.
Neuropsychologia
July 26, 2025
Jake Hooper, Devon Stoliker, Kyle Wolfe et al.
1 citation
Aesthetic experiences arise from an interplay of sensory, affective, and semantic processes. Psychedelics can profoundly alter these perceptions and evaluations, making them a valuable tool for investigating the neural basis of aesthetic experience. This article identifies synergies between psychedelic research and cognitive neuroscience to advance neuroaesthetics. It explores how psychedelic changes to sensory, affective, and semantic effects can inform understanding of neural mechanisms. The authors leverage existing theoretical frameworks and offer a preliminary agenda for future research.
December 10, 2025
Judith Hooper, Sarah Williams, Raeghan L. Mueller et al.
preprint
Among 365 current psilocybin users aged 18–77, younger adults (18–25) reported more adverse acute experiences, while older adults (55–77) had milder effects. Age did not significantly affect mystical experiences, psychological insight, or psychological outcomes. Polysubstance use patterns differed by age: younger adults more often co-used nicotine with psilocybin. Cannabis co-use with psilocybin was linked to greater perceived improvements in quality of life, anxiety, depression, and alcohol abuse, suggesting possible synergies between psilocybin and THC. The findings indicate that age and cannabis co-use may shape some of psilocybin’s acute effects and therapeutic outcomes.
PsyArXiv
October 18, 2024
Jake Hooper, Emily L Gyongyosi, Kent E. Hutchison et al.
preprint
Aesthetic qualities of psychedelic experiences—such as beauty, awe, and sensory richness—are linked to better therapeutic outcomes. In a cross-sectional survey, people who had recently used psilocybin, LSD, or DMT completed questionnaires about their acute experiences and later psychological well-being. Aesthetic experiences positively predicted emotional breakthroughs, psychological insight, mystical experiences, and general improvements in depression, anxiety, and quality of life. They were negatively associated with challenging experiences like fear and paranoia. The findings suggest that enhancing the aesthetic environment during psychedelic therapy could improve therapeutic benefits.
Cannabis and Cannabinoid Research
February 1, 2025
Margy Y. Chen, Emily B Kramer, Laurel P Gibson et al.
People who expect cannabis to improve their health tend to report greater acute reductions in tension after smoking cannabis flower, and greater increases in elation and reductions in pain after eating cannabis edibles. Among edible users, expecting cannabis to help with depression was linked to more elation, and expecting it to help with pain was linked to less pain. These expectancy effects occurred regardless of the product's THC and CBD levels, showing that users' beliefs shape some of the subjective effects of legal cannabis.
Cannabis and Cannabinoid Research
February 1, 2024
Laurel P Gibson, Raeghan L. Mueller, Evan A Winiger et al.
Regular cannabis users who self-administered commercially available edible products experienced increased intoxication and elation, decreased tension, and no change in paranoia two hours after use. Those who consumed a CBD-dominant product reported less intoxication than those who used a THC-only or THC+CBD product. Participants who used a THC+CBD product consumed less THC and had lower plasma THC levels than those using a THC-only product, yet reported similar positive and psychotomimetic effects. Psychotomimetic effects were very low across all conditions. The findings suggest that edible products containing CBD may allow experienced users to achieve desired effects with lower THC exposure, potentially reducing harm.
Cannabis and Cannabinoid Research
January 22, 2024
L. Bidwell, R. Martin-Willett, Carillon J. Skrzynski et al.
Among people with anxiety symptoms who used cannabis flower about three to four times per week over four weeks, those using CBD-dominant cannabis (24% CBD, <1% THC) reported lower anxiety on the Depression, Anxiety, and Stress Scale compared to those using THC-dominant cannabis (24% THC, <1% CBD), even after accounting for frequency of use. Immediately after use, CBD-dominant cannabis was also linked to lower tension and paranoia ratings than either THC-dominant or balanced THC+CBD (12% each) cannabis. All cannabis groups showed acute improvements in positive mood and some drug effects, and all reported reduced anxiety over the study period. The findings suggest that CBD-dominant forms may offer acute tension reduction that could support longer-term anxiety relief, without THC increasing anxiety.
Addiction Biology
January 1, 2022
Laurel P Gibson, Hollis C Karoly, Jarrod M. Ellingson et al.
Cannabis flower with both THC and CBD produces similar positive effects but less paranoia and anxiety than THC-dominant cannabis. In a naturalistic at-home study, 159 regular cannabis users were randomly assigned to one of three chemovars: THC-dominant (24% THC, 1% CBD), THC+CBD (9% THC, 10% CBD), or CBD-dominant (1% THC, 23% CBD). Plasma samples showed those using the CBD-dominant or THC+CBD chemovars had significantly less THC and more CBD than those using the THC-dominant chemovar. The THC+CBD chemovar yielded similar positive subjective effects but significantly less paranoia and anxiety compared to the THC-dominant chemovar, suggesting potential harm reduction from CBD.