Wayne Kepner
Postdoctoral Scholar, Psychiatry
Bio
Wayne Kepner, PhD, MPH is a public health researcher whose work examines how addiction treatment systems can be organized to support long-term recovery. He is an Instructor in the Department of Psychiatry and Behavioral Sciences at Stanford University School of Medicine, where he holds a NIDA Mentored Research Scientist Development Award (K01DA067040) as principal investigator. The award funds a five-year study of how medications for opioid use disorder and mutual help groups fit together in addiction treatment, along with development of a user-centered intervention to bridge the two. Dr. Keith Humphreys serves as his primary mentor and Dr. Mark McGovern as co-mentor. Dr. Kepner joined the Stanford faculty in 2026 after completing the school's NIDA T32 postdoctoral fellowship in Pain and Substance Use.
Dr. Kepner received his doctoral degree from the Joint Doctoral Program in Interdisciplinary Research on Substance Use at San Diego State University and the University of California, San Diego, and he holds an MPH from San Diego State University. His doctoral research addressed substance use disorders, health services utilization, and geospatial analysis of health data, with particular attention to older adult populations. Across more than thirty peer-reviewed publications, he has studied the implementation of low-threshold opioid treatment, emergency department utilization for substance-related diagnoses, national trends in stimulant and cannabis use, and harm reduction for older adults in opioid treatment programs. He works in both qualitative and quantitative traditions, with interviews of people who use drugs alongside analyses of large electronic health record and national survey datasets. Journalists at the Washington Post, CNN, and Forbes have covered his research, and the Urban Institute cited his work on stigma in its analysis of Oregon's Measure 110.
Alongside his academic work, Dr. Kepner maintains an active commitment to recovery communities and community-based organizations. He co-founded Aztecs For Recovery, the collegiate recovery program at San Diego State University, and he now advises SMART Recovery USA and Narcotics Anonymous World Services on research. He also serves on the board of the Asian American Drug Abuse Program, where he advises the implementation of a $20 million state grant to expand behavioral health services for Asian American and Pacific Islander communities.
Stanford Advisors
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Keith Humphreys, Postdoctoral Faculty Sponsor
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Mark McGovern, Postdoctoral Research Mentor
All Publications
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Substance use and treatment utilization patterns of working-age American men who were not in employment, education, or training (NEET) during the COVID-19 pandemic.
medRxiv : the preprint server for health sciences
2025
Abstract
A growing population of working-aged men are not in employment, education, or training (NEET). The COVID-19 pandemic increased rates of substance use disorders (SUDs) and affected treatment seeking in the general population, but the COVID era substance use patterns among NEET men are unknown.We estimated the prevalence and correlates of NEET status among working-aged (18-64) men using data from the 2022 National Survey on Drug Use and Health, a nationally representative survey of non-institutionalized individuals in the United States. We developed logistic regression models to examine associations between NEET status and substance use behaviors and treatment engagement, adjusted for sociodemographic factors.An estimated 11.1% of working-aged men were NEET in 2022 representing 10.6 million individuals. NEET men were significantly more likely to be older, have lower income, be unmarried, and have lower educational attainment and be Non-Hispanic Black compared to non-NEET men. After adjusting for sociodemographic factors, NEET status was significantly associated with higher odds of prescription tranquilizer/sedative use disorder (aOR = 3.54, 1.97-6.37), methamphetamine use disorder (aOR = 3.10, 95% CI: 1.82-5.28), and prescription pain reliever use disorder (aOR = 2.88, 1.82-4.53), while being inversely associated with alcohol use disorder (aOR = 0.68, 0.54-0.85).More than 1 in 10 working-aged men were NEET in 2022. Adjusted models showed higher odds of past-year SUDs but lower rates of alcohol use disorder. Targeted interventions should include age-appropriate, culturally tailored, and substance-specific treatment programs to improve public health.
View details for DOI 10.64898/2025.12.18.25342578
View details for PubMedID 41445637
View details for PubMedCentralID PMC12723769
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Prevalence and reasons for using cannabidiol, delta-8 tetrahydrocannabinol, cannabinol, cannabigerol, and hexahydrocannabinol among US adults.
Journal of cannabis research
2025; 7 (1): 100
Abstract
Since the passage of the 2018 US Farm Bill there has been a market for cannabinoid products derived from Cannabis sativa L. that contain < 0.3% delta-9 tetrahydrocannabinol (THC). Understanding the characteristics and motivations of cannabinoid product users is crucial for appropriate regulation of these products.We conducted a cross-sectional survey of 1,523 adults 18 years or older using the probability-based Ipsos KnowledgePanel, representative of 97% of US households. We assessed lifetime use of cannabidiol (CBD), delta-8 THC, cannabinol (CBN), cannabigerol (CBG), and hexahydrocannabinol (HHC), as well as self-reported reasons for using these products (i.e., medical vs. recreational). Using multivariable logistic regression models, we investigated associations of demographic and health behavior characteristics with product use. Lastly, we used the Medical Dictionary for Regulatory Activities to code medical reasons for cannabinoid product use into system organ class and preferred term categories.Lifetime use of CBD was 35.2% (95% CI 32.7-37.9), compared with 7.7% (95% CI 6.5-9.1) for delta-8 THC, 4.5% (95% CI 3.7-5.6) for CBN, 1.3% (95% CI 0.9-1.9) for CBG, and 1.5% (95% CI 1.0-2.1) for HHC. More adults used CBD for medical purposes (71.9%, 95% CI 68.9-74.7) than recreation (47.1%, 95% CI 43.9-50.3), which was also the case for CBN, CBG and HHC. Conversely, more adults used delta-8 THC for recreation (76.1% 95% CI 67.0-83.3) than for medical reasons (50.9; 95% CI 42.6-59.2). The most cited preferred terms for CBD use were anxiety (14.7%, 95% CI 13.0-16.6), pain (13.1%, 95% CI 11.5-15.0) and arthralgia (11.2%, 95% CI 9.5-13.2), for delta-8 THC use they were anxiety (18.6%, 95% CI 13.3-25.3), pain (15.2%, 95% CI 11.1-20.5) and insomnia (10.7%, 95% CI 7.4-15.3), and for CBN use they were insomnia (15.4%, 95% CI 9.6-23.9), pain (11.1%, 95% CI 6.4-18.7) and anxiety (10.9%, 95% CI 6.0-19.0).Use of cannabinoid products is appreciable, particularly CBD and delta-8 THC. Most adults use CBD, CBN, CBG, and HHC for medical reasons, but delta-8 THC for recreation. Pain, anxiety, insomnia and arthralgia were common medical reasons for use across the different cannabinoids assessed.
View details for DOI 10.1186/s42238-025-00359-8
View details for PubMedID 41366718
View details for PubMedCentralID PMC12690965
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Internet Searches for Lorazepam Following the Release of The White Lotus.
JAMA health forum
2025; 6 (11): e254931
Abstract
This cross-sectional study examines whether there was an uptick in online searches about lorazepam after the release of the third season of The White Lotus.
View details for DOI 10.1001/jamahealthforum.2025.4931
View details for PubMedID 41236765
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Differences in opioid use and overdose among younger and older justice-impacted adults.
Health & justice
2025; 13 (1): 63
Abstract
BACKGROUND: Justice-impacted persons aged 40 and up with substance use disorders (SUD) demonstrate increased health risks and health disparities relative to general population peers. Persons with SUD are less likely to age out of criminal behavior, appearing on criminal dockets, in jails, prisons, and under community supervision throughout the life course, with greater community-level cost burdens as they age. Justice system involvement presents health risks that compound with SUD to undermine well-being, which is amplified as people age and experience age-related health decline. Propensity for premature mortality from overdose is startlingly high for this population, highlighting demand for targeted policies to better meet the needs of this vulnerable group. To better understand justice-impacted older adults in treatment for SUD and inform policy, we examined opioid use outcomes among 357 low-income justice-impacted adults in SUD treatment in the Midwest, USA, including a natural oversampling of Black and American Indian or Alaska Native (AIAN) persons. We explored patterns among persons in their 40s, 50s, and 60s, relative to those under 40, conceptualizing life-course risk factors and using logistic regression to assess overdose, opioid use, and opioid agonist medication use.RESULTS: Significant differences in opioid use by age were observed, with older persons less likely to report opioid prescription misuse or illicit opioid use. Differences were not significant once controlling for user preferences, race/ethnicity, gender, family, childhood, and life course experiences. Overdose history was also significantly less likely for the 40 and older SUD patient, though this was no longer significant when controlling for demographic covariates. Opioid agonist medication use did not significantly differ by age.CONCLUSIONS: Justice-involved patients aged 40 and up in SUD treatment were less likely to have experienced overdose or report opioid use, relative to their younger peers, but this variation dissipated when considering demographic, family and/or life course factors. Targeted treatment services for gender and racial minorities may be beneficial for patients 40 and up. We identify preference for one substance, versus two, as protective against overdose and opioid use among older persons who use drugs.
View details for DOI 10.1186/s40352-025-00367-z
View details for PubMedID 41165970
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Three trajectories of implementation of medications for opioid use disorder in primary care.
Addiction science & clinical practice
2025; 20 (1): 69
View details for DOI 10.1186/s13722-025-00600-y
View details for PubMedID 40887602
View details for PubMedCentralID 11060908
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U.S. State Marijuana and Delta-8-Tetrahydrocannabinol Laws and Delta-8-Tetrahydrocannabinol Use.
American journal of preventive medicine
2025: 108026
Abstract
Delta-8-tetrahydrocannabinol has gained popularity since the passage of the 2018 U.S. Farm Bill. The absence of federal laws and varying state regulations governing delta-8-tetrahydrocannabinol have allowed manufacturers to evade restrictions placed on marijuana products. This study examined delta-8-tetrahydrocannabinol use across different state marijuana and delta-8-tetrahydrocannabinol policies.A cross-sectional, web-based survey of 1,523 U.S. adults was conducted in October-November 2023. Responses were weighted to represent the national adult population. Inverse-probability-of-treatment weights balanced covariates across policy groups; adjusted risk ratios and 95% CIs were estimated in 2025 for state (1) marijuana policy (prohibited, medical only, recreational) and (2) delta-8-tetrahydrocannabinol policy (prohibited, regulated, unregulated).Approximately 7.7% (95% CI=6.5, 9.1) of U.S. adults reported using delta-8-tetrahydrocannabinol in their lifetime. The prevalence of delta-8-tetrahydrocannabinol use was lower among adults in states permitting recreational marijuana use (5.5%; adjusted risk ratio=0.48, 95% CI=0.33, 0.70) and lower in states permitting medical use only (8.5%; adjusted risk ratio=0.73, 95% CI=0.46, 1.14) than in states prohibiting all marijuana use (10.9%). Adults in states that regulated (3.9%; adjusted risk ratio=0.33, 95% CI=0.20, 0.55) or prohibited (4.5%; adjusted risk ratio=0.47, 95% CI=0.28, 0.78) delta-8-tetrahydrocannabinol sales reported lower rates of delta-8-tetrahydrocannabinol use than adults in states with unregulated markets for delta-8-tetrahydrocannabinol (10.5%).Delta-8-tetrahydrocannabinol use is more common where marijuana remains prohibited and less common where delta-8-tetrahydrocannabinol sales are regulated or prohibited. State-level restrictions targeting delta-8-tetrahydrocannabinol appear to reduce use, suggesting that closing regulatory gaps could limit consumption of these products.
View details for DOI 10.1016/j.amepre.2025.108026
View details for PubMedID 40900067
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Effectiveness of Mutual Help Groups for Illicit Drug Use Disorders: A Review of the Current Literature (vol 12, 12, 2025)
CURRENT ADDICTION REPORTS
2025; 12 (1)
View details for DOI 10.1007/s40429-025-00659-2
View details for Web of Science ID 001482920800001
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Effectiveness of Mutual Health Groups for Illicit Drug Use Disorders: A Review of the Current Literature
CURRENT ADDICTION REPORTS
2025; 12 (1)
View details for DOI 10.1007/s40429-025-00635-w
View details for Web of Science ID 001416151400002
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Effectiveness of Mutual Help Groups for Illicit Drug Use Disorders: A Review of the Current Literature.
Current addiction reports
2025; 12
Abstract
Evaluate literature examining whether mutual help groups (MHGs) for illicit drug use disorders benefit participants.Recent studies consistently show that MHG attendance and involvement predict reductions in drug use and addiction severity. More rigorous methodologies offer stronger evidence of effectiveness, but additional controlled trials are needed. Drug-focused MHG challenges include lower success rates of professionally-delivered interventions to facilitate participation compared to alcohol-focused MHGs, and stigma towards opioid agonist medications. Culturally-tailored MHG formats may benefit specific populations (e.g., racial/ethnic minorities). Non-12 step MHGs like SMART Recovery show promise, but research is limited. Online delivery formats positively affect retention.Evidence on the benefits of MHGs for drug use disorders is encouraging but incomplete. MHG engagement may be enhanced by cultural adaptations and reduced stigma towards medications. Future research should focus on non-12 step MHGs, treatment integration, optimizing online formats, and understudied groups (e.g. Indigenous populations). Selection bias remains a challenge in evaluations of MHG effectiveness.
View details for DOI 10.1007/s40429-025-00635-w
View details for PubMedID 40831571
View details for PubMedCentralID PMC12360454
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Emergency care utilization in persons with substance related diagnoses.
Addictive behaviors reports
2024; 20: 100573
Abstract
Substance use is a significant contributor to emergency department (ED) visits. Little is known about ED utilization patterns of individuals with substance related diagnosis (SRD). We used electronic health records (EHR) from a large healthcare system in California to examine ED healthcare utilization and socio-demographic characteristics of individuals with SRDs.We used EHR data on all adult patients in our health system from April 2012 through September 2019 to conduct adjusted logistic regression models to determine socio-demographic correlates of SRDs (e.g., use, misuse, dependence) and associations between having an SRD and receiving emergency care.Among the sample (n = 342,651), the majority were female (55.08 %), Non-Hispanic White (58.10 %), with mean age of 48.26 (SD = 18.10), and there were 18,015 (5.26 %) individuals with an SRD. Patients with an alcohol-related diagnosis had the highest odds of visiting the ED (aOR = 3.75), followed by those with opioid (aOR = 3.57) and stimulant-related diagnoses (aOR = 3.48). Individuals with an SRD were more likely to identify as male, Black/African American, Hispanic/Latinx, have no health insurance, and have a serious mental illness. In the adjusted model, those with an SRD were significantly more likely to have ever received emergency care (aOR 3.72 [95 % CI 3.62-3.84]) than those without an SRD.Our study found an association between having an SRD and utilizing emergency health services. Demographic characteristics suggest disparities exist for those with SRDs around gender, race/ethnicity, insurance status, and mental health. These data can help with screening and targeted responses to prevent or provide emergency care.
View details for DOI 10.1016/j.abrep.2024.100573
View details for PubMedID 39687706
View details for PubMedCentralID PMC11647655