Importance:Understanding how cannabis legalization and large-scale societal disruptions influence adolescent cannabis use is important, as early use is associated with adverse health and educational outcomes. California has the largest regulated cannabis market in the US and provides a unique context to study how major policy and societal shifts are associated with adolescent cannabis use. Objective:To examine how rates of adolescent cannabis use in California changed after recreational cannabis legalization (RCL) and the COVID-19 pandemic. Design, Setting, and Participants:This population-based time-series cross-sectional study included adolescents aged 13 to 17 years in a large, integrated health care delivery system in California who were universally screened for cannabis use during standard pediatric care from January 2011 to December 2024. Data were analyzed from March to September 2025. Exposures:California state RCL passage (November 9, 2016), which reduced penalties for underage possession of cannabis; implementation of legal sales of cannabis for adults (January 1, 2018); and the COVID-19 pandemic (March 19, 2020). Main Outcomes and Measures:Any cannabis use in the past-year, self-reported based on universal screening at standard pediatric well-child visits. Interrupted time series analyses were fit using Poisson regression, standardized for sociodemographic characteristics of the adolescent Kaiser Permanente Northern California population. Results:The study included 1 308 655 screening questionnaires completed over the 14-year study period (mean [SD] 7789 [3673] adolescent screenings per month), with a mean (SD) age of 15.0 (1.4) years at screening and 666 881 (51.0%) questionnaires from female participants. Before RCL passage, the mean rate of adolescent cannabis use was decreasing, from 10.39% (95% CI, 9.96%-10.82%) in January 2011 to 6.83% (95% CI, 6.54%-7.14%) in October 2016 (annual trend rate ratio [RR], 0.93 [95% CI, 0.92-0.94] per year). Rates started increasing at the time of RCL passage (slope change RR, 1.19 [95% CI, 1.06-1.35]), and rates continued to increase after implementation of legal retail sales (annual trend RR, 1.06 [95% CI, 1.02-1.11] per year). After the COVID-19 pandemic began, rates of adolescent cannabis use decreased substantially (level change RR, 0.86 [95% CI, 0.76-0.97]; slope change RR, 0.80 [95% CI, 0.70-0.91]). Rates of adolescent cannabis use continued to decrease slightly in the years after COVID-19, reaching a mean of 6.45% (95% CI, 6.15%-6.77%) in December 2024 (annual trend RR, 0.98 [95% CI, 0.96-0.997] per year). Conclusions and Relevance:In this large, retrospective cross-sectional study, adolescent cannabis use increased following RCL and decreased following the COVID-19 pandemic, returning to prelegalization rates by 2024. These results have important implications for clinicians and policymakers and could help estimate future changes in adolescent cannabis use in response to broad policy changes and societal shifts and inform more effective prevention strategies.

Importance:As cannabis becomes more accessible and socially accepted, concerns have grown about its potential implications for adolescent mental health. While prior research has linked adolescent cannabis use to psychiatric symptoms, few large, population-based, longitudinal studies have examined associations with clinically diagnosed psychiatric disorders. Objective:To evaluate whether adolescent cannabis use is associated with an increased risk of incident psychotic, bipolar, depressive, and anxiety disorders during adolescence and young adulthood. Design, Setting, and Participants:This cohort study included adolescents aged 13 to 17 years who were screened for past-year cannabis use at Kaiser Permanente Northern California from 2016 to 2023. Adolescents were followed up through age 25 years or until December 31, 2023. Data were analyzed from February 21, 2024, to August 27, 2025. Exposure:Time-varying self-reported past-year cannabis use based on universal, confidential screening during standard pediatric care. Main Outcomes and Measures:Incident clinician-diagnosed psychotic, bipolar, depressive, and anxiety disorders, which were identified through electronic health records using International Classification of Disease codes. Cox proportional hazards regression models were used to measure the strength of associations between adolescent cannabis use and incident psychiatric diagnoses, with adjustments for sex, race and ethnicity, neighborhood deprivation index, insurance type, and time-varying alcohol and other substance use. Results:Of 463 396 adolescents (234 114 males [50.5%]; mean [SD] age, 14.5 [1.3] years) included in the sample, 136 708 were Hispanic individuals (29.5%), 93 737 were non-Hispanic Asian individuals (20.2%), 35 346 were non-Hispanic Black individuals (7.6%), 153 102 were non-Hispanic White individuals (33.0%), and 18 795 individuals were multiracial or of other races or ethnicities (4.1%). At baseline, 26 345 adolescents (5.7%) self-reported past-year cannabis use. Past-year cannabis use was associated with an increased risk of incident psychotic (adjusted hazard ratio [AHR], 2.19; 95% CI, 1.97-2.42), bipolar (AHR, 2.01; 95% CI, 1.82-2.22), depressive (AHR, 1.34; 95% CI, 1.30-1.39), and anxiety disorders (AHR, 1.24; 95% CI, 1.21-1.28). The strength of the associations between cannabis use and incident depressive and anxiety disorders decreased as adolescents aged. This pattern was similar but slightly attenuated after additional adjustment for past psychiatric conditions (psychotic disorder: AHR, 1.92; 95% CI, 1.73-2.13; bipolar disorder: AHR, 1.73; 95% CI, 1.57-1.90; depressive disorder: AHR, 1.33; 95% CI, 1.29-1.38; anxiety disorder: AHR, 1.19; 95% CI, 1.16-1.23). Conclusions and Relevance:This cohort study found that adolescent cannabis use was associated with increased risk of incident psychiatric disorders, particularly psychotic and bipolar disorders. These results could inform the development of clinical and educational interventions for parents, adolescents, and clinicians, as well as protective policies to prevent or delay adolescent cannabis use in the context of expanding cannabis legalization.

BACKGROUND:Cannabis marketing exposure has been shown to influence use among youth by increasing positive cannabis perceptions and interest. However, little is known about what specific cannabis advertising features influence youth's perceptions, a key precursor to youth use. METHODS:Respondents consisted of 409 youth (age 16-20 years) surveyed in 2022 who reported susceptibility to using cannabis and were living in California, which legalized adult-use cannabis sales in 2018. Using an online experiment, respondents were randomly assigned to view cannabis advertisements with and without features previously shown to be appealing to adolescents, followed by questions related to cannabis perceptions. Exploratory factor analysis identified three underlying types of cannabis perceptions following ad exposure: cannabis as fun, healthy, or dangerous. Multivariable ordered logistic regressions tested associations of specific advertisement content features with these perceptions. RESULTS:Results revealed features that created perceptions of cannabis as fun, including depictions of positive sensations, psychoactive appeal, food or flavor references, the use of illustrated imagery, and animals or creatures. Features associated with perceptions of cannabis as healthy included positive sensations, adventure, showing the product, and price information. Ads depicting heavy consumption, faces, socializing, and using cannabis to avoid negative moods resulted in youth perceptions of cannabis as dangerous, and those with food or flavor references were perceived as less dangerous. CONCLUSION:Results provide new insight into the psychological pathways by which marketing may operate. This can inform marketing standards and regulations to limit the effects of cannabis marketing on youth.

BACKGROUND:Prenatal cannabis use is increasing, and pregnant individuals often seek guidance from cannabis retailers. It is unknown whether budtender messaging varies by community social vulnerability. METHODS:This cross-sectional mystery shopper study included 505 randomly selected California licensed cannabis retailers (2/26/2024-1/28/2025). Social vulnerability within a 15-minute drive-time buffer around retailers was measured by the CDC Social Vulnerability Index (SVI; range 0-1; four domains: socioeconomic status, household characteristics, racial/ethnic minority status, housing/transportation). The primary outcome was a 4-category prenatal cannabis risk communication measure: clear risk messaging [reference], mode-specific lower-risk messaging, no clear safety/risk messaging, and safety-affirming messaging. Secondary outcomes included product recommendations, fetal or infant health risks, information sources, and guidance to consult a clinician. Logistic and multinomial logistic regression models assessed associations between SVI and outcomes; SVI was multiplied by 10, so estimates reflect odds associated with a 0.1 increase in SVI. RESULTS:Greater household vulnerability was associated with safety-affirming messaging (OR=1.26;95%CI:1.01-1.56) and no clear safety/risk messaging (OR=1.25; 95%CI:1.05-1.50) versus clear risk messaging. Greater racial/ethnic minority vulnerability was associated with safety-affirming versus clear risk messaging (OR=1.21; 95%CI:1.00-1.47). Greater housing/transportation vulnerability was associated with mode-specific lower-risk messaging versus clear risk messaging (OR=1.42; 95%CI:1.06-1.91). Citing warnings was more common in areas with greater socioeconomic vulnerability (OR=1.23; 95%CI:1.01-1.51). Other outcomes did not differ by SVI. CONCLUSIONS:Budtenders in more vulnerable areas were more likely to provide safety-affirming, mode-specific lower-risk, or no clear safety/risk messaging rather than clear prenatal cannabis risk messaging. Findings highlight the need for consistent, evidence-based communication in retail settings.

Abstract Background Cannabis legalization has substantial impacts on public health across the United States, yet the perspectives of local elected officials who oversee regulatory environments and make decisions about cannabis business retail licensing, taxation, and marketing restrictions remain largely unstudied. Understanding how these policymakers prioritize health considerations relative to economic and other concerns is essential for developing effective public health advocacy and anticipating barriers to implementing health-protective cannabis regulations. Methods From September 2023 to February 2024, we conducted an online survey of 2,681 elected officials in California local government, assessing cannabis policy positions, priorities, and engagement. Descriptive statistics were calculated for all measures. Likelihood ratio tests using logistic regression assessed differences across political party affiliations (Democrat, Republican, Independent), with analyses stratified by whether respondents’ jurisdictions allowed cannabis retail. One open-ended measure was analyzed using thematic coding. Results Among 250 respondents (9.3% response rate), who were primarily city council members, 40% reported direct cannabis policy experience and 75% expressed interest in regulatory involvement. Top priorities were tax revenue (41%), economic development (41%), and youth cannabis use (38%), reflecting tension between fiscal and health considerations. Support for licensing adult-use retailers was significantly higher among Democrats (72%) than Republicans (39%; OR = 0.25 [95% CI: 0.11, 0.56]) or Independents (38%; OR = 0.23 [0.10, 0.53]). Republicans were significantly more likely to prioritize adverse health effects (47% vs. 22% Democrats; OR = 3.10 [1.36, 7.07]). Social equity was prioritized by only 13% overall, with significant partisan variation (20% Democrats vs. 3% Republicans; OR = 0.11 [0.01, 0.85]). Cross-party agreement emerged on restricting youth-attractive packaging (84%), yet fewer than 4% of California jurisdictions that allow retail to operate have implemented such protections. Qualitative responses revealed diverse framings of cannabis—from prohibition-era moral concerns to wellness narratives—suggesting policy decisions are often not evidence-based. Conclusions This first systematic study of U.S. elected officials’ cannabis policy positions documents a political landscape in which economic considerations predominate over health concerns and significant gaps exist between policymakers’ support for health-protective measures and actual policy implementation. These findings identify actionable opportunities for evidence-based public health advocacy, particularly in support of bipartisan youth protection measures.

Objective: The study investigated whether California storefront and non-storefront cannabis retailers are adhering to online age-gating requirements and whether differences in website marketing practices exist. Methods: Websites of 134 storefront and 115 non-storefront licensed retailers were randomly selected. Bivariate associations were tested between retailer type and website marketing, age-gating methods, and presence of age-gating at various purchase stages. Results: Among the 200 (80.3%) websites with age-gating when entering, 182 (91%) employed an ineffective method where users click either “Yes” or “No” to confirm their age. Moreover, 49 (19.68%) websites lacked age-gating when entering. Amongst those requiring photo identification during checkout (n = 100, 40.16%), 97% allowed users to proceed after uploading an irrelevant image. Significantly more storefront retailers employed combined age-gating at entry, mandatory account registration, and age-gating during checkout than non-storefront retailers (X2 (1, N = 249) = 7.69, p < .01). Retailer websites frequently displayed “clean” labels (n = 200, 80.32%), followed by positive state claims (n = 198, 79.52%), physical health claims (n = 166, 66.67%), and mental health claims (n = 146, 58.63%). Significantly more storefront retailers displayed physical health claims (X2 (1, N = 249) = 7.52, p < .01) and health warnings than non-storefront retailers (X2 (1, N = 249) = 4.13, p = .04). Conclusions: Most cannabis retailers comply with age-gating requirements; however, methods employed are easily circumvented. Youths’ easy and unrestricted access to cannabis retailer websites may increase positive attitudes about cannabis and encourage use.

OBJECTIVE:We evaluated associations between prenatal cannabis use and major structural birth defects of the child. METHODS:This population-based retrospective cohort study comprised singleton births (January 2011-July 2020) universally screened for substance use at entrance to prenatal care. Prenatal cannabis use was defined as self-reported use or a positive toxicology test during pregnancy. Electronic health record and birth certificate data were used to identify 38 specific major structural birth defects within 8 organ systems (i.e., central nervous, eye, ear, cardiac, orofacial/respiratory, gastrointestinal, genitourinary/renal, and musculoskeletal). Modified Poisson regression models were conducted adjusting for propensity scores. RESULTS:Of 363,952 infants, 22,494(6.2%) were exposed to maternal prenatal cannabis use, and 6094 infants (2.17%) had a major structural birth defect. Maternal prenatal cannabis use was associated with gastroschisis in the unadjusted (RR = 2.00, 95% CI: 1.25-3.19) and other non-cannabis prenatal substance use (aRR = 1.68; 95% CI: 1.04-2.71) adjusted models, but not in the models adjusted for maternal age or the propensity score. Maternal prenatal cannabis use was associated with omphalocele in the unadjusted model (RR = 3.04; 95% CI: 1.42-6.48), maternal age-adjusted model (aRR = 3.54; 95% CI: 1.68-7.48), other prenatal substance use-adjusted model (aRR = 3.31; 95% CI: 1.50-7.31), and propensity score adjusted model (aRR: 2.92, 95% CI: 1.26-6.77). Cases of gastroschisis and omphalocele were rare: n = 172 (0.05%) and n = 48 (0.01%), respectively. No associations emerged between maternal prenatal cannabis use and any other birth defects. Findings were replicated when cannabis was defined by toxicology testing only. CONCLUSIONS:Maternal prenatal cannabis use was associated with an increased risk for gastroschisis and omphalocele. Clinicians should provide counseling in a supportive manner to pregnant individuals about the potential harms associated with prenatal cannabis use.

[This corrects the article DOI: 10.1371/journal.pgph.0001219.].

Background: California boasts the largest regulated cannabis market in the world, but it is increasingly exposing youth to cannabis marketing, and the state's definition of content appealing to youth is vague. We aimed to identify the specific features of California cannabis ads that increase interest in cannabis use among adolescents to inform reasonably restrictive marketing policy. Methods: Participants consisted of 409 youth (age 16-20 years) susceptible to using cannabis in the future and living in California. Using an online experiment, participants were randomly assigned to view cannabis ads with and without features previously shown to be appealing to adolescents, followed by questions about attitudes toward the ad and their interest in using the advertised cannabis product or service. Multivariable regressions tested associations of content features with these outcomes. Results: Several features were significantly associated with increasing youth interest in cannabis use and attitudes toward the ad following ad exposure, including illustration, clear product descriptions, food or flavor references, depictions of positive sensations, adventure, psychoactive effects, and references to heavy consumption. Conclusion: California cannabis ads contain features that appeal to youth and that are not restricted in California or other U.S. states with legal cannabis retail.

Importance Pregnant individuals seeking information about the safety of prenatal cannabis use may view budtenders (individuals who work at cannabis retailers) as a trusted source of information. However, the recommendations that budtenders provide to pregnant individuals considering cannabis use are unknown. Objective To characterize how budtenders respond to questions about the safety of blunt, tobacco, and cannabis use during pregnancy, and to evaluate whether advice varied by indication for use or by whether the retailer provided delivery. Design, Setting, and Participants In this cross-sectional study of California cannabis retailers, mystery shoppers posed as pregnant individuals looking for advice about the safety of prenatal substance use. Telephone calls with randomly selected licensed storefront retailers were conducted from February 26, 2024, to January 28, 2025. Exposures Mystery shoppers followed 2 versions of a script (mental health vs no mental health indications for use) with questions about the safety of prenatal blunt, tobacco, and cannabis use. Main Outcomes and Measures The primary outcome was retailers’ responses about the safety of prenatal blunt, tobacco, and cannabis use. Secondary outcomes included product recommendations, opinions on safer vs more harmful modes of prenatal cannabis use, and whether to speak with a physician. Results Of the 505 employees at selected retailers (ie, budtenders), 79.6% (95% CI, 74.8%-83.7%) said prenatal blunt use was unsafe, 79.2% (95% CI, 74.4%-86.4%) said prenatal tobacco use was unsafe, and 40.4% (95% CI, 35.1%-45.9%) said prenatal cannabis use was unsafe. More advised that prenatal cannabis use was safe (20.6%; 95% CI, 16.0%-26.1%) vs blunts (0.8%; 95% CI, 0.2%-2.9%) or tobacco (0.8%; 95% CI, 0.2%-2.9%) or stated that they could not give advice about the safety of prenatal cannabis (19.8%; 95% CI, 15.3%-25.2%) vs tobacco (14.3%; 95% CI, 10.5%-19.2%). Only 5.7% (95% CI, 4.0%-8.1%) mentioned store or product warnings. Budtender recommendations included low- or no-tetrahydrocannabinol cannabis products, harm reduction (eg, use less frequently), and noncannabis strategies (eg, mindfulness). Edibles were most endorsed as safe, while smoking was most endorsed as harmful. Overall, 44.0% (95% CI, 37.3%-50.8%) recommended speaking to a physician before prompting and 46.1% (95% CI, 39.4%-53.0%) after prompting. Responses were generally similar regardless of stated indication for use or delivery service availability. Conclusions and Relevance In this cross-sectional study, most budtenders advised against prenatal blunt and tobacco use. Fewer advised against prenatal cannabis use, highlighting the need for more visible, effective warnings and mandatory budtender education covering risks of prenatal cannabis use.

BACKGROUND:Local policies prohibiting cannabis sales and lower cannabis retail availability are associated with a lower prevalence of adolescent cannabis use. In this study, we examined whether local prohibitions on cannabis retail and cannabis retailer proximity and density are associated with adverse cannabis-related mental health outcomes among adolescents. METHODS:Cross-sectional study of 95,645 Northern California adolescents aged 13-17 who completed a well-check questionnaire in 2021 during standard pediatric care. Exposures included local bans on cannabis storefront and delivery retailers, and retail proximity and density in relation to adolescents' geocoded residences. Past-year psychotic, depressive, and anxiety disorders were identified using ICD codes; self-reported depression symptoms came from the questionnaire. RESULTS:Relative to adolescents in jurisdictions allowing storefront and delivery retail, those in jurisdictions prohibiting storefront retail only (aPR = 0.52; 95%CI: 0.32-0.85), or prohibiting both (aPR = 0.67; 95%CI: 0.48-0.92) had a lower prevalence of psychotic disorders. Greater retailer density (≥6 vs. 0 retailers within a 15-min drive) was associated with a greater prevalence of anxiety disorders (aPR = 1.11; 95%CI: 1.04-1.19), depressive disorders (aPR = 1.10; 95%CI: 1.02-1.19) and depression symptoms (aPR = 1.08; 95%CI: 1.01-1.15). Having a ≥20-min (vs. <5-min) drive to the nearest retailer was associated with a lower prevalence of psychotic (aPR = 0.53; 95%CI: 0.33-0.86), anxiety (aPR = 0.89; 95%CI: 0.82-0.97), and depressive disorders (aPR = 0.89; 95%CI: 0.81-0.98) and depression symptoms (aPR = 0.91; 95%CI: 0.84-0.99). CONCLUSIONS:Local policies prohibiting storefront retail were associated with a lower prevalence of psychotic disorders. Greater retail availability of cannabis near adolescents' residences was associated with a greater prevalence of psychotic, anxiety, and depressive disorders, and depression symptoms. Policies limiting retail density and availability may help reduce cannabis-related harms and merit further assessment.

(Abstracted from JAMA Health Forum 2024;5(11):e243656) In the United States, the rates of self-reported prenatal cannabis use rose from 3% in 2002 to 7% in 2017. Pregnant individuals say that they use cannabis for mental health and physical symptoms and because they believe it is safer than medications for those ailments.

INTRODUCTION:One of the few studies on cannabis home deliveries reported that 97 % of census block groups in California were reached by a cannabis delivery business. This suggests but does not prove that many cannabis deliverers are violating local delivery bans throughout the state. This study estimated the extent of such violations to assess the need for enforcing local bans on non-medical cannabis delivery and the relevance of expanding home deliveries of medical cannabis to any part of California (i.e. Senate Bill (SB) 1186). METHODS:Adults who used cannabis in the past month were selected from the 2021 and 2022 California Health Interview Surveys (n = 6841). Delivery policies affecting study participants were determined by linking residential coordinates and corresponding jurisdictions to the California Cannabis Local Laws database. Associations between delivery policy and use of a delivery service were tested in logit models. RESULTS:The two principal findings were the high percentage of deliveries to banned jurisdictions (37.6 %) and the null association between a delivery ban and use of a delivery service (aOR=1.01(0.75,1.35)). Although exclusive medical users had significantly greater odds of home delivery than non-medical cannabis users (aOR=1.93(1.28, 2.91); p < .01), the association was not moderated by delivery policy. CONCLUSIONS:Violation of local cannabis delivery bans was common practice in California in 2021 and 2022. While subsequent enactment of Senate Bill 1186 reduced local delivery restrictions on medical cannabis, delivery bans on non-medical cannabis remain common. Thus, jurisdictions that ban the activity should consider greater enforcement of delivery laws.

PURPOSE:Although most US states with legalized recreational cannabis retail (RCR) allow some degree of local control, the impact of local policy on cannabis use has seldom been studied. Changes in self-reported cannabis use by California 11th graders pre- and post-RCR legalization (January 2018) were examined, overall and by local policy. METHODS:Adjusted interrupted time-series multilevel models assessed changes in past 30-day cannabis use post-RCR and tested whether such changes differed by local city and county allowance of storefront and delivery cannabis sales. Cross-sectional data from the 2015/2016 to 2019/2020 California Healthy Kids Surveys were analyzed (n = 377,205). RESULTS:Stable pre-RCR odds of any past 30-day cannabis use increased after legalization (odds ratio [OR] [Δ level]: 1.06, p = .013) among all jurisdictions except for those allowing medical delivery only-which decreased-and then slowly declined (OR [Δ slope]: 0.97, p = .001) among all jurisdictions except for those newly allowing storefronts and delivery retail, where elevated rates persisted. Pre-RCR legalization odds of frequent use decreased, whereas post-RCR, they increased through spring 2020 (OR [Δ level]: 1.30, p < .001; OR [Δ slope]: 1.13, p < .001) with no differential changes by local policy. Odds of recent cannabis use and frequent cannabis use were lower in retail-banning jurisdictions without pre-RCR medical sales compared to those allowing storefronts. DISCUSSION:Frequent cannabis use among California 11th graders increased post-RCR legalization. After an increase in any 30-day use, use in retail-banning jurisdictions declined, whereas rates in jurisdictions newly permitting storefronts and delivery remained raised. Lower cannabis use in retail-banning jurisdictions pre-RCR suggests pre-existing norms potentially spurred local policies.

Background: As more states legalize cannabis, studies are needed to understand the potential impacts of recreational cannabis legalization (RCL) on adolescents from the perspective of clinicians who care for them. Methods: This qualitative study characterized clinician perspectives on whether cannabis legalization is associated with changes in adolescents ' cannabis use beliefs, behaviors, and consequences. Semi -structured qualitative interviews were conducted with 32 clinicians in a large healthcare organization from 9/6/2022 -12/21/2022. Video -recorded interviews were transcribed and analyzed using thematic analysis. Results: The 32 participants (56.3 % female, mean [SD] age, 45.9 [7.6] years; 65.3 % non -Hispanic White) were from Addiction Medicine (n = 13), Psychiatry/Mental Health (n = 7), Pediatrics (n = 5), and the Emergency Department (n = 7). Clinicians described post-RCL increases in adolescent cannabis use, use of non-combustible modes and high -potency products, and younger age of first use. Clinicians reported social, physical, and policy changes, including changes in social norms, appealing advertisements, marketing, and easier access. Many noted fewer perceived harms among adolescents and greater self -medication post-RCL. They described how RCL contributed to increased parental cannabis use and permissiveness around adolescent use. Finally, many described post-RCL increases in cannabis hyperemesis syndrome, and several noted increased cannabis -related psychosis and acute intoxication, and decreased court -mandated treatment. Conclusions: Clinicians from diverse specialties described post-RCL increases in adolescent cannabis use and cannabis -related consequences, alongside changes in social norms, access, marketing and advertisements, and decreased perceptions of harms. Findings can inform strategies to support adolescents in the context of increased cannabis availability and acceptability post -legalization and support the development of hypotheses for broaderscale quantitative work.

OBJECTIVE:To evaluate the feasibility and accuracy of an unprecedented COVID-19 antigen testing program in schools, which required a healthcare provider order, laboratory director, a Clinical Laboratory Improvement Amendments certificate of waiver, as well as training of school personnel. STUDY DESIGN:Descriptive report of a point-of-care, school-based antigen testing program in California from August 1st, 2021 through May 30, 2022, in which participants grades K-12 self-swabbed and school personnel performed testing. Participants included 944 009 students, personnel, and community members from 4022 California kindergarten through high schools. Outcomes measured include sensitivity and specificity (with polymerase chain reaction [PCR] as comparator) of the Abbott BinaxNOW antigen test, number of tests performed, and active infections identified. RESULTS:Of 102 022 paired PCR/antigen tests, the overall sensitivity and specificity for the antigen test was 81.2% (95% CI: 80.5%-81.8%) and 99.6% (95% CI: 99.5%-99.6%), respectively, using cycle threshold values <30. During January through March 2022, the highest prevalence period, the positive predictive value of antigen testing was 94.7% and the negative predictive value was 94.2%. Overall, 4022 school sites were enrolled and 3 987 840 million antigen tests were performed on 944 009 individuals. A total of 162 927 positive antigen tests were reported in 135 163 individuals (14.3% of persons tested). CONCLUSIONS:Rapidly implementing a school-based testing program in thousands of schools is feasible. Self-swabbing and testing by school personnel can yield accurate results. On-site COVID-19 testing is no longer necessary in schools, but this model provides a framework for future infectious disease threats.

Objectives. To examine whether local cannabis policies and retail availability are associated with cannabis use and problematic cannabis use (PCU) among adolescents in Northern California. Methods. The sample comprised adolescents aged 13 to 17 years screened for past-year cannabis use during well-child visits in 2021. Exposures included local bans on cannabis storefront retailers, policy protectiveness, and retail proximity and density. Outcomes included self-reported past-year cannabis use and PCU diagnoses. Modified Poisson regression models adjusted for sociodemographics. Results. The sample (n = 103 134) was 51.1% male with a median age of 15 years (interquartile range [IQR] = 14-16 years); 5.5% self-reported cannabis use, and 0.3% had diagnosed PCU. Adolescents had a lower prevalence of cannabis use in jurisdictions that banned storefront retailers (adjusted prevalence rate [APR] = 0.857; 95% confidence interval [CI] = 0.814, 0.903 vs allowed), banned delivery (APR = 0.751; 95% CI = 0.710, 0.795 vs allowed), or had more policy protections (APR range = 0.705-0.800). Lower PCU prevalence was also found among those in jurisdictions that banned (vs allowed) storefront retailers (APR = 0.786; 95% CI = 0.629, 0.983) or delivery (APR = 0.783; 95% CI = 0.616, 0.996). Longer drive time and lower density of storefront retailers were associated with a lower cannabis use prevalence. Conclusions. More protective cannabis policies and less retail availability were associated with a lower prevalence of adolescent cannabis use and PCU. (Am J Public Health. 2024;114(S8):S654-S663. https://doi.org/10.2105/AJPH.2024.307787).

AIMS:The aim of this study is to identify cannabis products according to their appeal among young adults and measure product sales trends. DESIGN, SETTING AND PARTICIPANTS:This was a retrospective comparative study using point-of-sale data from licensed recreational cannabis retailers that include buyer age with birth year entered by retailers, set in California, USA. Cannabis purchases by young adults (aged 21-24, GenZ) were compared with older adults (age 25+) over 4 years (2018-21). MEASUREMENTS:Sales for six cannabis product categories were analyzed using a commercial data set with imputations and a raw data set. Age-appeal metrics were dollar and unit sales to young adults, and dollar and unit share ratios (young adults/older adults), where a share ratio of 100 denotes age-appeal comparability. A product category was considered more young-adult appealing than others if its mean on a metric was at least one standard deviation above the grand mean across all product categories. FINDINGS:Flower (cannabis plant material) and vapor pen appealed to young adults based on absolute dollar sales, dominating young-adult spending compared with other cannabis products (37.24 and 31.83%, respectively). Vapor pen and concentrate appealed to young adults based on dollar share ratios of 152, meaning these products comprised a 52% greater share of young-adult cannabis spending relative to older-adult spending (31.83/20.97% and 10.47/6.88%, respectively). Less appealing to young adults were pre-roll, edible/beverage and absorbable products (tincture/sublingual, capsule and topical). Flower showed the largest dollar sales growth (B = +$3.50 million/month), next to vapor pen (B = +$1.55 million/month). Vapor pen tied for highest growth in the percent of product dollars from the largest package size (B = +0.85%/month) and showed the steepest price decline (B = -0.53 price per gram/month). CONCLUSIONS:In California, USA, from 2018 to 2021, relative to older adults, young adults spent a greater share of their cannabis dollars on vapor pen and concentrate (products with high potency of delta-9-tetrahydrocannabinol).

Importance:Many studies have evaluated whether in utero cannabis exposure is associated with fetal and neonatal outcomes, yet little is known about whether prenatal cannabis use is associated with maternal health outcomes during pregnancy. Objective:To evaluate whether prenatal cannabis use is associated with maternal health outcomes during pregnancy. Design, Setting, and Participants:This population-based retrospective cohort study included pregnancies in Northern California from January 2011 to December 2019 that lasted 20 weeks or longer and were screened for prenatal cannabis use. Exposures:Prenatal cannabis use was defined as any self-reported use during early pregnancy or a positive toxicology test result based on universal screening at entrance to prenatal care (approximately 8-10 weeks' gestation). Self-reported frequency of use (daily, weekly, monthly or less, never, unknown), use defined only by self-report, and use defined only by toxicology test results were examined. Main Outcomes and Measures:Electronic health record data were used to define the following outcomes: gestational hypertension, preeclampsia, eclampsia, gestational diabetes, gestational weight gain greater and less than guidelines, placenta previa, placental abruption, placenta accreta, and severe maternal morbidity. Adjusted risk ratios (aRRs) were calculated using a modified Poisson regression. Results:The sample (n = 316 722 pregnancies; 250 221 unique individuals) included 84 039 (26.5%) Asian/Pacific Islander, 20 053 (6.3%) Black, 83 145 (26.3%) Hispanic, and 118 333 (37.4%) White individuals; the mean (SD) age was 30.6 (5.4) years. Overall, 20 053 (6.3%) screened positive for prenatal cannabis use; 2.9% were positive by self-report, 5.3% by toxicology testing, and 1.8% by both. The frequency of cannabis use was 1930 (0.6%) daily, 2345 (0.7%) weekly, 4892 (1.5%) monthly or less, and 10 886 (3.4%) unknown. Prenatal cannabis use was associated with greater risk of gestational hypertension (aRR, 1.17; 95% CI, 1.13-1.21), preeclampsia (aRR, 1.08; 95% CI, 1.01-1.15), weight gain less than (aRR, 1.05; 95% CI, 1.01-1.08) and greater than (aRR, 1.09; 95% CI, 1.08-1.10) guidelines, and placental abruption (aRR, 1.19; 95% CI, 1.05-1.36). The pattern of results was similar when defining prenatal cannabis use only by self-report or only by toxicology testing, and associations between the frequency of prenatal cannabis use and outcomes varied with outcome. Conclusions and Relevance:The results of this cohort study suggest that prenatal cannabis use was associated with several adverse maternal health outcomes during pregnancy. Continued research is needed to understand whether characteristics of prenatal cannabis use (eg, dose, mode, and timing) moderate these associations.