Adolescent Cannabis Use and Cognitive Effects: Research and Long-Term Impact

Executive Summary

Adolescent cannabis use has emerged as one of the most scrutinized public health questions in the legalization era, with mounting evidence suggesting the developing brain faces unique vulnerabilities between ages 12 and 25. Recent research from UC San Diego and other institutions indicates that regular cannabis consumption during adolescence correlates with measurable changes in executive function, memory consolidation, and attention span—effects that may persist into adulthood depending on frequency, potency, and age of initiation. As 24 states plus Washington D.C. have legalized adult-use cannabis and medical programs serve patients as young as pediatric epilepsy cases, policymakers, parents, and clinicians confront a complex risk-benefit calculus. The endocannabinoid system undergoes critical maturation during adolescence, making this developmental window particularly sensitive to exogenous cannabinoids like THC. While catastrophic claims of permanent IQ loss have not held up under rigorous longitudinal analysis, subtler deficits in working memory, impulse control, and educational attainment appear consistently in heavy adolescent users. This topic hub synthesizes two decades of neuroscience, epidemiology, and policy research to provide operators, investors, advocates, and families with an evidence-based foundation for understanding cognitive risk in the youth cannabis debate.

Why This Matters

Adolescent cognitive effects sit at the intersection of public health, regulatory design, and the social license that sustains the legal cannabis industry. Approximately 22% of U.S. high school seniors reported past-year cannabis use in 2025, according to the Monitoring the Future survey conducted by the University of Michigan. This represents roughly 1.2 million adolescents annually engaging with a substance that remains federally illegal and carries age-restriction warnings in every legal state. For state regulators, adolescent use rates serve as a key performance indicator. Legalization opponents cite any uptick in youth consumption as evidence of policy failure, while proponents argue that regulated markets reduce adolescent access compared to prohibition. Colorado, the first adult-use state, has seen teen use rates remain flat or decline slightly since 2014 legalization, per the Colorado Department of Public Health and Environment—a data point frequently invoked in legislative debates nationwide. For multi-state operators (MSOs) and ancillary businesses, youth prevention is both a compliance obligation and a reputational imperative. Trulieve, Curaleaf, Green Thumb Industries, and Cresco Labs collectively spend millions annually on responsible-use campaigns and retail compliance training to prevent underage sales. A single high-profile case of youth access can trigger emergency regulatory action, as seen when Massachusetts temporarily suspended delivery licenses in 2023 after minors obtained products using fake IDs. For parents and educators, the question is immediate and personal: does occasional experimentation cause lasting harm, or is the risk confined to chronic heavy use? Pediatricians report fielding this question weekly as cannabis normalization accelerates. The American Academy of Pediatrics maintains opposition to legalization largely on adolescent neurodevelopment grounds, while organizations like the Multidisciplinary Association for Psychedelic Studies argue that evidence-based harm reduction—not abstinence-only messaging—better serves youth. For medical cannabis patients, the stakes are clinical. Pediatric epilepsy patients in states like California and New York access high-CBD, low-THC formulations under physician supervision, raising questions about therapeutic ratios and long-term safety. The FDA approved Epidiolex (pharmaceutical CBD) in 2018 for Dravet syndrome and Lennox-Gastaut syndrome in patients as young as two years old, establishing a regulatory precedent for cannabinoid therapy in developing brains under controlled conditions.

Background and History

The scientific investigation of cannabis and adolescent cognition began in earnest in the 1990s, driven by neuroimaging advances and longitudinal cohort studies tracking youth development.

Early Research and the Dunedin Study (1990s-2012)

The modern evidence base traces to the Dunedin Multidisciplinary Health and Development Study, a New Zealand birth cohort launched in 1972 that followed 1,037 individuals from birth into adulthood. In 2012, Duke University researcher Madeline Meier published findings in the Proceedings of the National Academy of Sciences showing that persistent cannabis use beginning in adolescence correlated with an average 8-point IQ decline by age 38, even after cessation. The study defined persistent use as meeting DSM-IV cannabis dependence criteria in three or more waves of assessment between ages 18 and 38, with earlier onset predicting greater decline. The Dunedin findings dominated policy discourse for years, cited in legislative testimony opposing legalization in states from Florida to Ohio. However, subsequent reanalysis by Ole Rogeberg of the Ragnar Frisch Centre for Economic Research in 2013 suggested that socioeconomic confounding—not cannabis per se—might explain much of the IQ effect. Rogeberg demonstrated that individuals from lower socioeconomic backgrounds both used cannabis more heavily and experienced IQ declines independent of use, raising questions about causal attribution.

Neuroimaging Era (2010-2020)

Functional MRI and diffusion tensor imaging studies in the 2010s shifted focus from IQ to specific neural structures. Research teams at institutions including Harvard Medical School, Northwestern University, and the University of Montreal documented volumetric differences in the hippocampus, amygdala, and prefrontal cortex among adolescent cannabis users compared to non-users. A 2014 study in The Journal of Neuroscience by Jodi Gilman found that even casual use (1-2 times per week) in 18-25 year-olds correlated with altered gray matter density in reward-processing regions. Critics noted that many early neuroimaging studies suffered from small sample sizes (n=20-40) and failed to control for alcohol co-use, tobacco, and pre-existing psychiatric conditions. A 2015 meta-analysis in JAMA Psychiatry by Nora Volkow, director of the National Institute on Drug Abuse (NIDA), concluded that while structural differences were detectable, their functional significance remained unclear—some differences might represent adaptation rather than damage.

ABCD Study Launch (2015-Present)

The Adolescent Brain Cognitive Development (ABCD) Study, launched by the National Institutes of Health in 2015, represents the largest long-term study of brain development and child health in U.S. history. Enrolling 11,880 children aged 9-10 at baseline across 21 sites, ABCD tracks participants with annual neuroimaging, cognitive testing, and substance use surveys through age 20. Early ABCD publications (2019-2025) provide the cleanest data on pre-use brain structure, allowing researchers to distinguish pre-existing vulnerabilities from cannabis-induced changes. A 2023 ABCD analysis published in JAMA Network Open found that adolescents who initiated cannabis use by age 14 showed accelerated thinning of the prefrontal cortex compared to matched controls, with effects dose-dependent on frequency. Importantly, the study found no differences in cortical thickness at baseline (age 9-10), suggesting the changes emerged after use began.

High-Potency THC Concerns (2018-Present)

The rise of high-potency products—concentrates, vape cartridges, and edibles exceeding 70-90% THC—has intensified adolescent risk concerns. Average THC content in seized cannabis samples increased from approximately 4% in 1995 to 15% in 2021, according to the University of Mississippi's Potency Monitoring Program. Concentrates and vapes, which dominate youth consumption patterns, routinely exceed 80% THC. Research by Madeline Meier (the Dunedin study author) published in 2022 in Lancet Psychiatry found that adolescents using high-potency products daily showed four times the rate of psychotic symptoms compared to non-users, and double the rate compared to low-potency flower users. This finding spurred regulatory action: Vermont capped THC at 60% for concentrates in 2020, and Connecticut imposed a 30% THC cap for flower in its 2021 legalization bill (later revised to 35% after industry lobbying).

COVID-19 Pandemic Impact (2020-2022)

Adolescent cannabis use patterns shifted during pandemic lockdowns. The 2021 Monitoring the Future survey showed a decline in past-month use among 12th graders (from 23.9% in 2020 to 19.5% in 2021), attributed to reduced social access. However, emergency department visits for cannabis-related psychiatric crises in adolescents increased 23% in 2020-2021, per CDC data, suggesting that users who continued consumed more heavily or turned to higher-potency products.

Recent Research: UC San Diego and Beyond (2024-2026)

The May 2026 UC San Diego study referenced in triggering news represents the latest wave of research leveraging ABCD data and advanced machine learning. While full publication details remain embargoed, preliminary findings presented at the Society for Neuroscience annual meeting in November 2025 indicated that working memory deficits in adolescent users persist up to 28 days after cessation, with recovery trajectories varying by cumulative exposure. Lead researcher Dr. Krista Lisdahl noted that deficits were most pronounced in tasks requiring sustained attention and cognitive flexibility—functions mediated by the dorsolateral prefrontal cortex, which continues myelination through age 25.

Key Players

National Institute on Drug Abuse (NIDA)

NIDA, part of the National Institutes of Health, funds approximately 85% of U.S. research on cannabis and adolescent cognition. Director Nora Volkow has led the agency since 2003, consistently emphasizing adolescent vulnerability in congressional testimony. NIDA's budget for cannabis research reached $195 million in fiscal year 2025, with $68 million directed specifically to developmental neuroscience. The agency operates the Drug Supply Program, which until 2021 provided only low-potency (8% THC) cannabis for research—a limitation that drew criticism for failing to reflect market realities. In 2021, NIDA contracted with the University of Mississippi to cultivate higher-potency strains (up to 25% THC) for research purposes.

American Academy of Pediatrics (AAP)

The AAP, representing 67,000 pediatricians, published a comprehensive policy statement in 2015 opposing cannabis legalization, reaffirmed in 2023. The organization cites adolescent neurodevelopment as the primary rationale, alongside concerns about impaired driving and gateway effects. The AAP supports decriminalization of possession and medical cannabis access for specific pediatric conditions (epilepsy, chemotherapy-induced nausea) but opposes recreational legalization. The organization's stance influences state medical societies and legislative testimony nationwide.

Smart Approaches to Marijuana (SAM)

SAM, founded in 2013 by former U.S. Representative Patrick Kennedy and psychiatrist Kevin Sabet, positions adolescent brain science as the cornerstone of its anti-legalization advocacy. The organization has testified in opposition to legalization bills in over 30 states, frequently citing the Dunedin study and high-potency concerns. SAM receives funding from philanthropic sources including the Julie and Jonathan Sackler Foundation and individual donors; the organization does not disclose pharmaceutical industry contributions but has faced accusations of accepting such funding.

Multidisciplinary Association for Psychedelic Studies (MAPS)

MAPS, a drug policy reform organization, advocates for harm reduction approaches to adolescent cannabis use rather than abstinence-only messaging. The organization argues that exaggerated risk claims undermine credibility with youth and that evidence-based education—acknowledging both risks and the reality of widespread use—better serves public health. MAPS has funded research on therapeutic applications of cannabinoids in adolescent populations, including CBD for anxiety disorders.

Multi-State Operators (MSOs)

Major MSOs including Truliev, Curaleaf, Green Thumb Industries, and Cresco Labs fund youth prevention initiatives as part of social equity and regulatory compliance strategies. Curaleaf's "Cannabis Responsibility Coalition" spent $4.2 million in 2024-2025 on school-based prevention programs in Florida, Massachusetts, and New Jersey. Industry critics note that these campaigns mirror Big Tobacco's youth prevention efforts in the 1990s—initiatives that served public relations goals while companies continued marketing practices that appealed to youth.

Researchers and Institutions

Key research groups include the University of Colorado Boulder's CUChange lab (director: Kent Hutchison), McLean Hospital's Imaging Center (director: Staci Gruber), UC San Diego's Center for Human Development (director: Krista Lisdahl), and the Montreal Neurological Institute (researcher: Patricia Conrod). These teams contribute to the ABCD Study and conduct independent longitudinal research. Funding sources include NIDA, state health departments, and in some cases cannabis tax revenue earmarked for research (as in Colorado and Washington).

Legal and Regulatory Framework

Federal law prohibits cannabis possession and use at any age under the Controlled Substances Act, 21 U.S.C. § 812, which classifies cannabis as a Schedule I substance. This classification—denoting high abuse potential and no accepted medical use—has remained unchanged since 1970, though a 2024 DEA notice of proposed rulemaking (NPRM) proposed rescheduling to Schedule III. The NPRM process remains pending as of May 2026, with over 43,000 public comments submitted during the initial comment period.

State Age Restrictions

All 24 adult-use states set the minimum purchase age at 21 years, mirroring alcohol policy. This threshold reflects political compromise rather than neuroscience—brain development continues through age 25, but a 25-year-old minimum was deemed politically and practically unworkable. Vermont considered a 25-year-old minimum during its 2018 legalization debate but settled on 21 after economic impact analyses projected a 40% reduction in market size.

Medical Cannabis and Minors

38 states with medical cannabis programs allow minors to access products with parental consent and physician recommendation. Qualifying conditions typically include epilepsy, cancer, autism spectrum disorder, and terminal illness. States impose varying restrictions:

• California: Minors may access medical cannabis with a physician recommendation and parental consent; no age floor. High-CBD products are most commonly recommended for pediatric patients.
• New York: Minors may participate in the medical program with two physician certifications (one must be a pediatric specialist) and parental consent. THC content is capped at 10% for patients under 18.
• Florida: Minors may access medical cannabis for terminal conditions or with two physician certifications for other qualifying conditions. Smokable flower is prohibited for patients under 18.
• Ohio: Minors may access medical cannabis with physician recommendation and parental consent; a second physician opinion is required for patients under 16.

Underage Use Penalties

States vary widely in penalties for underage possession. Most adult-use states treat first-time possession by minors as a civil violation (fine) rather than a criminal offense:

• Colorado: First offense is a $100 fine plus mandatory drug education; second offense is $250 fine; third offense may involve juvenile court referral.
• Massachusetts: Civil penalty of $100 for first offense; substance abuse assessment required for subsequent offenses.
• Illinois: Civil violation with fines ranging from $100-$500; community service may be imposed.
• Washington: First offense is a civil infraction with a $50 fine; subsequent offenses may be referred to juvenile court.

Retailer Penalties for Underage Sales

Legal states impose severe penalties on retailers who sell to minors, typically including:

• Fines ranging from $10,000 to $100,000 per violation
• License suspension (30-90 days for first offense)
• License revocation for repeat violations
• Criminal charges against individual employees who completed the sale

Massachusetts suspended three delivery licenses for 90 days in 2023 after compliance checks revealed sales to individuals using fake IDs. Nevada revoked a dispensary license in 2022 after two documented underage sales within a six-month period.

Federal Research Barriers

The Schedule I classification creates significant barriers to adolescent cannabis research. Researchers must obtain a DEA license, navigate institutional review board concerns about studying illegal substances, and until recently could only access low-potency cannabis from the NIDA Drug Supply Program. The 2018 Farm Bill's legalization of hemp (cannabis with <0.3% THC) enabled some CBD research without DEA licensure, but THC research remains heavily restricted.

State-by-State Breakdown

Adolescent use rates and regulatory approaches vary significantly across states, influenced by legalization status, medical program design, and prevention funding.

Colorado

Colorado legalized adult-use cannabis in 2012 (sales began 2014) and has the longest track record on adolescent use patterns post-legalization. The Colorado Department of Public Health and Environment's Healthy Kids Colorado Survey found that past-month use among high school students declined from 21.2% in 2015 to 18.4% in 2023. However, use of concentrates and vapes increased, with 12.3% of high school users reporting daily or near-daily consumption in 2023 (up from 8.1% in 2015). Colorado dedicates $9.5 million annually from cannabis tax revenue to youth prevention programs, including the "Good to Know" campaign and school-based interventions.

California

California legalized adult-use cannabis in 2016 (Proposition 64), with sales beginning in 2018. The California Healthy Kids Survey showed past-month use among 11th graders at 15.8% in 2021-2022, down from 18.3% in 2017-2018. The state requires cannabis retailers to contribute to a Youth Education, Prevention, Early Intervention and Treatment Account, which distributed $28 million in grants in fiscal year 2024-2025. California imposes no THC caps but requires packaging to include warnings about adolescent brain development risks.

Washington

Washington legalized adult-use cannabis in 2012 (sales began 2014) and maintains one of the most robust adolescent monitoring systems. The Healthy Youth Survey found that 8th-grade past-month use remained stable at approximately 5% from 2014-2023, while 10th-grade use declined from 17.8% to 14.2%. Washington dedicates $6.3 million annually to prevention, including media campaigns and community coalitions. The state also funds the Marijuana Impact Evaluation, a longitudinal research program tracking health and social outcomes.

Massachusetts

Massachusetts legalized adult-use cannabis in 2016 (sales began 2018) and imposes a 3% local option tax that municipalities may dedicate to prevention. The Youth Risk Behavior Survey showed past-month use among high school students at 22.7% in 2021, comparable to pre-legalization rates (23.1% in 2015). The state Cannabis Control Commission allocated $4.8 million to the Youth Education and Prevention Program in fiscal year 2025, funding school-based curricula and community partnerships.

Michigan

Michigan legalized adult-use cannabis in 2018 (sales began 2019) and directs $20 million annually from cannabis revenue to K-12 education, including prevention programs. The Michigan Profile for Healthy Youth survey found past-month use among 11th graders at 19.3% in 2023, down slightly from 20.1% in 2019. The state requires retailers to post signage warning that cannabis use before age 21 may harm brain development, per Michigan Compiled Laws § 333.27959.

Illinois

Illinois legalized adult-use cannabis in 2019 (sales began 2020) and allocates 25% of cannabis tax revenue to the Restore, Reinvest, and Renew (R3) Program, which includes youth prevention. The Illinois Youth Survey showed past-month use among high school students at 16.2% in 2022, comparable to pre-legalization rates. The state imposes mandatory ID scanning at dispensaries and conducts quarterly compliance checks, with a 98.7% compliance rate in 2024.

New York

New York legalized adult-use cannabis in 2021 (sales began 2023) and directs 20% of cannabis tax revenue to drug treatment and education programs. The Youth Risk Behavior Survey showed past-month use among high school students at 20.8% in 2023, down from 22.4% in 2019. New York's Office of Cannabis Management launched the "Talk2Prevent" campaign in 2024, providing parents with evidence-based conversation guides about adolescent cannabis risks.

Ohio

Ohio legalized adult-use cannabis via ballot initiative in November 2023 (Issue 2), with sales beginning in August 2024. Pre-legalization data from the Ohio Youth Risk Behavior Survey showed past-month use among high school students at 17.6% in 2023. The state's Division of Cannabis Control is required to establish a youth prevention program funded by 3% of cannabis tax revenue, but implementation details remain under development as of May 2026.

Market and Business Implications

Adolescent cognitive effects influence market structure, product development, compliance costs, and investment risk across the cannabis industry.

Product Reformulation and Potency Caps

Regulatory pressure to limit adolescent access to high-potency products has driven product innovation and reformulation. Vermont's 60% THC cap on concentrates (effective 2020) forced manufacturers to dilute extracts with carrier oils or terpenes, creating a new product category marketed as "enhanced flower" or "infused pre-rolls." Some operators exited the Vermont market entirely, citing compliance costs and reduced margins. Connecticut's 30% THC cap for flower (later revised to 35%) in its 2021 legalization statute faced immediate industry opposition. Cultivators argued that modern genetics routinely exceed 30% THC and that the cap would drive consumers to the illicit market. The legislature revised the cap to 35% before the first dispensary opened, but the debate illustrated the tension between public health goals and market realities.

Compliance and Age Verification Costs

Preventing underage sales requires robust ID verification systems, employee training, and compliance monitoring. Industry estimates suggest that age verification infrastructure costs retailers $15,000-$30,000 annually per location, including:

• ID scanning hardware and software ($5,000-$10,000 initial investment; $200-$500 monthly subscription)
• Employee training programs ($100-$200 per employee annually)
• Compliance audits and mystery shopper programs ($5,000-$10,000 annually)
• Legal and regulatory consulting ($5,000-$10,000 annually)

Curaleaf, which operates 150+ dispensaries across 18 states, reported $4.7 million in compliance-related costs in its 2024 annual report, with age verification representing approximately 30% of that total.

Insurance and Liability

Underage sales create significant liability exposure for operators. General liability insurance premiums for cannabis retailers range from $5,000 to $25,000 annually, with rates increasing 20-40% for operators with documented compliance violations. Some insurers exclude coverage for underage sales entirely, leaving operators exposed to uninsured losses in the event of a lawsuit.

Investment Due Diligence

Institutional investors and MSOs conducting acquisition due diligence scrutinize target companies' compliance records, particularly underage sales violations. A single documented underage sale can reduce acquisition valuations by 5-10% or trigger earnout provisions that delay payment. Private equity firms including Poseidon Asset Management, Tuatara Capital, and Merida Capital report that compliance history is a top-three diligence priority, alongside financial performance and regulatory risk.

Marketing Restrictions and Appeal to Youth

State regulations prohibit marketing that appeals to minors, typically banning:

• Cartoon characters or imagery appealing to children
• Celebrity endorsements by individuals under 21
• Advertising within 1,000 feet of schools or playgrounds
• Billboards on highways where more than 30% of the audience is under 21
• Sponsorship of events where more than 30% of attendees are under 21

Enforcement varies widely. Massachusetts fined a dispensary $50,000 in 2023 for Instagram posts featuring imagery the Cannabis Control Commission deemed appealing to minors (cartoon-style illustrations of cannabis leaves). Colorado issued warnings to multiple operators in 2022 for packaging that resembled mainstream candy brands.

What Experts Say

Scientific consensus holds that adolescent cannabis use, particularly frequent use of high-potency products, poses measurable cognitive risks, but experts disagree on magnitude, reversibility, and policy implications. Dr. Nora Volkow, director of the National Institute on Drug Abuse, has stated in congressional testimony that "the adolescent brain is particularly vulnerable to the effects of cannabis because it is still undergoing active development." Volkow points to neuroimaging studies showing altered connectivity in the prefrontal cortex and disrupted white matter development in adolescent users. She advocates for delaying initiation as long as possible and emphasizes that daily or near-daily use poses the greatest risk. Dr. Krista Lisdahl, director of the Brain Imaging and Neuropsychology Laboratory at the University of Wisconsin-Milwaukee and a lead investigator on ABCD Study analyses, has described the evidence as showing "dose-dependent effects, with heavy users showing the most pronounced deficits in executive function and memory." In a 2024 interview with Science magazine, Lisdahl noted that "occasional use—once or twice a month—shows minimal detectable effects in most studies, but weekly or daily use is where we see consistent cognitive impacts." Dr. Staci Gruber, director of the Marijuana Investigations for Neuroscientific Discovery (MIND) program at McLean Hospital, has emphasized the importance of distinguishing between correlation and causation. According to Gruber, "many adolescents who use cannabis heavily also have pre-existing risk factors—ADHD, anxiety, trauma—that independently affect cognitive development. Teasing apart cannabis effects from these confounds is the central challenge." Gruber's research has found that cognitive deficits in adolescent users often improve after sustained abstinence, suggesting some effects are reversible. Dr. Kevin Sabet, co-founder of Smart Approaches to Marijuana, has argued that "the science is clear enough to justify a precautionary approach. We don't need perfect evidence to protect developing brains—we have enough evidence of risk to warrant keeping cannabis illegal for adults and certainly for adolescents." Sabet frequently cites the Dunedin study and high-potency concerns in media appearances and legislative testimony. Dr. Carl Hart, professor of psychology at Columbia University and author of Drug Use for Grown-Ups, has criticized what he describes as "exaggerated claims about adolescent cannabis risks that ignore socioeconomic context and serve prohibitionist agendas." Hart argues that "the vast majority of adolescents who use cannabis do not experience lasting cognitive impairment, and focusing on worst-case scenarios distorts public understanding and policy." Hart advocates for harm reduction approaches that acknowledge both risks and the reality of widespread use. The American Academy of Pediatrics, in its 2023 policy statement, concluded that "current evidence supports the conclusion that regular cannabis use during adolescence is associated with impairments in attention, learning, and memory that may persist beyond the period of acute intoxication." The AAP recommends that pediatricians screen adolescents for substance use, provide brief interventions, and refer heavy users to treatment.

What's Next

The adolescent cannabis and cognition research agenda for 2026-2030 will focus on longitudinal ABCD Study outcomes, high-potency product effects, and intervention efficacy.

ABCD Study Milestones

The ABCD Study cohort will reach ages 18-19 in 2026-2027, providing the first large-scale data on the transition from adolescent to young adult use patterns. Researchers will analyze whether early adolescent use (ages 12-14) predicts heavier use in late adolescence, and whether cognitive deficits observed at age 16-17 persist, worsen, or resolve by age 20. Results are expected in peer-reviewed publications beginning in late 2026.

High-Potency Product Research

NIDA has prioritized research on concentrates, vapes, and edibles exceeding 70% THC. The agency issued $12 million in grants in 2025 for studies comparing cognitive effects of high-potency versus low-potency products in controlled settings. Results are expected in 2027-2028 and will inform regulatory debates over potency caps.

State Policy Experiments

Several states are considering or implementing novel regulatory approaches:

• Vermont is evaluating whether its 60% THC cap on concentrates has reduced adolescent use of high-potency products. A state-funded evaluation is due in December 2026.
• Washington is piloting a "cannabis report card" that will grade products on potency, contaminants, and other factors, with the goal of steering consumers toward lower-risk options.
• New York is considering a tiered tax structure that imposes higher rates on products exceeding 25% THC, with revenue earmarked for youth prevention.

Federal Rescheduling and Research Access

If the DEA completes rescheduling cannabis to Schedule III, research barriers will ease significantly. Schedule III substances (including ketamine and anabolic steroids) face less stringent DEA oversight, and researchers will gain access to a wider range of products for study. The rescheduling process includes a public hearing before an administrative law judge (ALJ), tentatively scheduled for fall 2026, with a final rule potentially issued in 2027.

Prevention Program Evaluations

States are beginning to evaluate the efficacy of cannabis tax-funded prevention programs. Colorado commissioned a third-party evaluation of its "Good to Know" campaign, with results expected in mid-2026. Early indicators suggest that media campaigns have limited impact on use rates but may influence perceptions of risk and delay age of initiation.

Clinical Interventions

Research on interventions for adolescent cannabis use disorder is expanding. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) and NIDA are funding trials of motivational interviewing, cognitive-behavioral therapy, and family-based interventions tailored to adolescent users. A 2025 pilot study at Yale University found that a smartphone app delivering personalized feedback on cognitive performance and use patterns reduced consumption by 30% in heavy adolescent users over 12 weeks.

Further Reading

• Adolescent Brain Cognitive Development (ABCD) Study: https://abcdstudy.org
• National Institute on Drug Abuse (NIDA) Cannabis Research: https://nida.nih.gov/research-topics/cannabis-marijuana
• Meier, M. H., et al. (2012). "Persistent cannabis users show neuropsychological decline from childhood to midlife." Proceedings of the National Academy of Sciences, 109(40), E2657-E2664. https://www.pnas.