Psychedelic medicine (New Rochelle, N.Y.)
March 1, 2024
Justin C Strickland, Albert Garcia-Romeu, Matthew W Johnson
20 citations
Brief four- and seven-item versions of the Mystical Experience Questionnaire (MEQ-4) and Challenging Effects Questionnaire (CEQ-7) show strong correspondence with the full 30- and 26-item scales. In a sample of 1,160 individuals who used psychedelics therapeutically outside research settings, total scores for the brief versus full versions correlated at r = 0.89 for the MEQ and r = 0.90 for the CEQ. Classic psychedelics like LSD and psilocybin produced higher scores on both brief and full versions than MDMA. Higher mystical experience scores on both versions were linked to greater reductions in depression and anxiety, while challenging experiences showed limited association with mental health changes. The brief scales substantially reduce participant burden while maintaining validity.
Journal of psychopharmacology (Oxford, England)
May 1, 2025
Sean P Goldy, Benjamin A Du, Julia S Rohde et al.
15 citations
Classic psychedelics carry both greater acute challenging effects and persisting negative effects compared to cannabis, but also produce greater positive acute and persisting effects. In two studies using quota-based sampling to approximate US Census demographics, participants reported on their first or most memorable experiences with either substance. Predictors of psychedelic outcomes—such as dose level, presence of others, religiosity, and personality—explained only a small degree of the variation. The findings offer a more nuanced characterization of the risks and benefits of psychedelic experiences relative to cannabis.
Advances in pharmacology (San Diego, Calif.)
January 1, 2022
Justin C Strickland, Matthew W Johnson
13 citations
The past decade has seen rapid growth in research on the basic science and clinical understanding of psychedelics. This chapter reviews the human behavioral pharmacology of three classic psychedelics: psilocybin, LSD, and DMT. It covers historical background, drug classification, and special considerations such as set and setting, mystical experience measurement, blinding, placebos, and abuse liability. The subjective, physiological, and clinical effects of these substances are described, documenting a unique collection of acute and long-term behavioral changes. Clinical research shows potential therapeutic utility in difficult-to-treat conditions like treatment-resistant depression, alcohol use disorder, and cigarette smoking. Future work is needed to reveal mechanisms of behavior change.
Journal of psychopharmacology (Oxford, England)
January 1, 2026
Jack E Henningfield, Sandra D Comer, Matthew L Banks et al.
5 citations
A panel of abuse potential experts convened to discuss challenges in assessing the abuse potential of novel drugs, especially psychedelics and cannabinoids. The U.S. Controlled Substances Act scheduling process, intended to balance public safety with medicinal access, can be overly restrictive when abuse potential is overestimated, as postmarketing evaluations have suggested for some substances. Existing methods recommended by the FDA are generally reliable for many drug categories but require modifications—such as behavioral economic assessments and broader outcome measures in human abuse potential studies—to accurately characterize newer agents. The commentary emphasizes the need for updated approaches to ensure valid scheduling decisions that protect public health without hindering access to beneficial medicines.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
November 1, 2025
Justin C Strickland, Hayleigh E Tilton, Noah M Patton et al.
Caffeine co-administered with THC produced minimal changes in subjective effects, performance, or metabolism, though signals for perceived driving impairment were observed. In contrast, CBD co-administered with THC and caffeine increased outcomes associated with abuse liability and performance impairment versus THC alone. CBD also increased plasma THC and 11-OH-THC concentrations. These data provide the first direct assessment of pharmacodynamic and pharmacokinetic effects of THC and caffeine co-administered in humans, emphasizing the importance of considering full cannabinoid profiles and drug combinations in regulatory decision-making.
ACS pharmacology & translational science
June 11, 2021
Justin C Strickland, Albert Garcia-Romeu, Matthew W Johnson
correction
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