Hollis Karoly, PhD

Publications

• Pince CL, Stallsmith VT, Piercey CJ, Weldon K, Ruehrmund J, Dooley G, Bidwell LC, Karoly HC. Cannabis administration is associated with reduced alcohol consumption: Evidence from a novel laboratory co-administration paradigm. Drug Alcohol Depend. 2025 Aug 27;276:112860. [Epub ahead of print] PubMed PMID: 40915022
• Piercey CJ, Bunch J, Cameron J, Ahern R, Packwood I, Bruning C, Henry D, Ruehrmund J, Weldon K, Smith KE, Karoly HC. Kratom use among ethnobotanical tea bar patrons in Colorado: Subjective drug effects, adverse reactions, and perceived benefits of use. Drug Alcohol Depend Rep. 2025 Sep;16:100361. PubMed PMID: 40823326
• Piercey CJ, Pince CL, Karoly HC. Highlighting variability in fentanyl test strip instructions using thematic content analysis. Harm Reduct J. 2025 Jun 24;22(1):110. PubMed PMID: 40551121
• Prince MA, Paez B, Morse JL, Gray BA, Karoly H, McFarland NM, Emery NN, Crabtree MA, Swaim RC. "Other" Substance Use Among American Indian Reservation-Area High School Youth. J Stud Alcohol Drugs. 2025 May 20. [Epub ahead of print] PubMed PMID: 40391457
• Grodin EN, Karoly H, Browning BD, Coleman L, Farokhnia M, Kryszak LA, Meredith LR, Squeglia LM. Utilizing blood inflammatory markers in alcohol studies: Considerations and recommendations for study design, sample collection, and data analysis. Neurosci Biobehav Rev. 2025 Jun;173:106142. PubMed PMID: 40216171
• Piercey CJ, Schlechter TE, Henry D, Allen-Collins M, Ahern R, Cameron J, Conner BT, Snodgrass JG, Karoly HC. Use of reagent test kits and fentanyl test strips among electronic music festival attendees in Colorado: prevalence, barriers, and behavior in response to drug checking. Harm Reduct J. 2025 Apr 2;22(1):46. PubMed PMID: 40176104
• Gowin JL, Ellingson JM, Karoly HC, Manza P, Ross JM, Sloan ME, Tanabe JL, Volkow ND. Brain Function Outcomes of Recent and Lifetime Cannabis Use. JAMA Netw Open. 2025 Jan 2;8(1):e2457069. PubMed PMID: 39874032
• Karoly HC, Kirk-Provencher KT, Schacht JP, Gowin JL. Alcohol and brain structure across the lifespan: A systematic review of large-scale neuroimaging studies. Addict Biol. 2024 Sep;29(9):e13439. PubMed PMID: 39317645
• Piercey CJ, Mataczynski M, Stallsmith VT, Emery NN, Karoly HC. Examining Associations Between Cannabis Use Disorder and Measures of Weekly and Within-Day Cannabis Frequency, Quantity, and Potency in College Students. Cannabis Cannabinoid Res. 2024 Jun;9(3):e917-e923. PubMed PMID: 37699241
• Sznitman SR, Martin-Willett R, Ma W, Karoly HC, Bidwell LC. Daily diary study of associations between alcohol, cannabis, co-use and sleep quality in individuals with intentions to use cannabis to cope with anxiety. Drug Alcohol Rev. 2024 Feb;43(2):501-511. PubMed PMID: 37985016
• Douglass MA, Stanley LR, Karoly HC, Prince MA, Crabtree MA, Swaim RC. Patterns of Simultaneous and non-Simultaneous Use of Cannabis and Alcohol Among American Indian Adolescents. Addict Res Theory. 2024;32(5):339-345. PubMed PMID: 39479370
• Karoly HC, Prince MA, Conner BT. Alcohol First, Cannabis Last: Identification of an Especially Risky Use Pattern among Individuals Who Co-Use Alcohol and Cannabis. Subst Use Misuse. 2024;59(3):343-352. PubMed PMID: 37853738
• Ross JM, Karoly HC, Zellers SM, Ellingson JM, Corley RP, Iacono WG, Hewitt JK, McGue M, Vrieze S, Hopfer CJ. Evaluating substance use outcomes of recreational cannabis legalization using a unique co-twin control design. Am J Drug Alcohol Abuse. 2023 Sep 3;49(5):630-639. PubMed PMID: 37262386
• Ross JM, Karoly HC, Zellers SM, Ellingson JM, Corley RP, Iacono WG, Hewitt JK, McGue M, Vrieze S, Hopfer CJ. Addendum to "Evaluating substance use outcomes of recreational cannabis legalization using a unique co-twin control design". Am J Drug Alcohol Abuse. 2023 Sep 3;49(5):684. PubMed PMID: 38014892
• Karoly HC, Drennan ML, Prince MA, Zulic L, Dooley G. Consuming oral cannabidiol prior to a standard alcohol dose has minimal effect on breath alcohol level and subjective effects of alcohol. Psychopharmacology (Berl). 2023 May;240(5):1119-1129. PubMed PMID: 36939855
• Karoly HC, Conner BT, Prince MA. Associations between alcohol and cannabis use order, frequency, quantity, and consequences in a college sample of individuals who co-use alcohol and cannabis. Am J Addict. 2023 May;32(3):283-290. PubMed PMID: 36546556
• Martin-Willett R, Skrzynski CJ, Karoly HC, Elmore JS, Bidwell LC. Baseline affective symptomatology moderates acute subjective effects of high potency THC and CBD cannabis concentrates. Exp Clin Psychopharmacol. 2023 Dec;31(6):1039-1049. PubMed PMID: 37289543
• Gibson LP, Karoly HC, Ellingson JM, Klawitter J, Sempio C, Squeri JE, Bryan AD, Bidwell LC, Hutchison KE. Effects of cannabidiol in cannabis flower: Implications for harm reduction. Addict Biol. 2022 Jan;27(1):e13092. PubMed PMID: 34467598
• Bidwell LC, Karoly HC, Torres MO, Master A, Bryan AD, Hutchison KE. A naturalistic study of orally administered vs. inhaled legal market cannabis: cannabinoids exposure, intoxication, and impairment. Psychopharmacology (Berl). 2022 Feb;239(2):385-397. PubMed PMID: 34708254
• Karoly HC, Milburn MA, Brooks-Russell A, Brown M, Streufert J, Bryan AD, Lovrich NP, DeJong W, Cinnamon Bidwell L. Effects of High-Potency Cannabis on Psychomotor Performance in Frequent Cannabis Users. Cannabis Cannabinoid Res. 2022 Feb;7(1):107-115. PubMed PMID: 33998859
• Bidwell LC, Martin-Willett R, Karoly HC. Advancing the science on cannabis concentrates and behavioural health. Drug Alcohol Rev. 2021 Sep;40(6):900-913. PubMed PMID: 33783029
• Karoly HC, Mueller RL, Andrade CC, Hutchison KE. THC and CBD effects on alcohol use among alcohol and cannabis co-users. Psychol Addict Behav. 2021 Sep;35(6):749-759. PubMed PMID: 33764086
• Karoly HC, Ross JM, Prince MA, Zabelski AE, Hutchison KE. Effects of cannabis use on alcohol consumption in a sample of treatment-engaged heavy drinkers in Colorado. Addiction. 2021 Sep;116(9):2529-2537. PubMed PMID: 33464670
• Karoly HC, Skrzynski CJ, Moe EN, Bryan AD, Hutchison KE. Exploring relationships between alcohol consumption, inflammation, and brain structure in a heavy drinking sample. Alcohol Clin Exp Res. 2021 Nov;45(11):2256-2270. PubMed PMID: 34523725
• Karoly HC, Ross JM, Ellingson JM, Feldstein Ewing SW. Exploring Cannabis and Alcohol Co-Use in Adolescents: A Narrative Review of the Evidence. J Dual Diagn. 2020 Jan-Mar;16(1):58-74. PubMed PMID: 31519143
• Karoly HC, Mueller RL, Bidwell LC, Hutchison KE. Cannabinoids and the Microbiota-Gut-Brain Axis: Emerging Effects of Cannabidiol and Potential Applications to Alcohol Use Disorders. Alcohol Clin Exp Res. 2020 Feb;44(2):340-353. PubMed PMID: 31803950
• Thayer RE, Hansen NS, Prashad S, Karoly HC, Filbey FM, Bryan AD, Feldstein Ewing SW. Recent tobacco use has widespread associations with adolescent white matter microstructure. Addict Behav. 2020 Feb;101:106152. PubMed PMID: 31639638
• Bidwell LC, Ellingson JM, Karoly HC, YorkWilliams SL, Hitchcock LN, Tracy BL, Klawitter J, Sempio C, Bryan AD, Hutchison KE. Association of Naturalistic Administration of Cannabis Flower and Concentrates With Intoxication and Impairment. JAMA Psychiatry. 2020 Aug 1;77(8):787-796. PubMed PMID: 32520316

Practice Locations

UCHealth University of Colorado Hospital (UCH)
12605 E. 16th Ave
Aurora, CO 80045
720-848-0000

Specialty Information

Specialties

• Psychology