Hair cannabinoid levels in adolescents predicted changes in sleep, exercise, and mental health one year later
In the national ABCD Study, THC concentrations in adolescent hair predicted shorter sleep duration and more strength exercise a year later, with effects differing between males and females.
Quick Facts
What This Study Found
Among 2,262 youth ages 9-15, greater hair THC concentrations predicted more frequent strength exercise one year later; greater CBD concentrations predicted fewer strength exercise days; and greater THCCOOH concentrations predicted shorter sleep duration. Effects differed by sex: among males, THC and THCCOOH predicted shorter sleep; among females, THC and THCCOOH predicted strength exercise frequency and THC predicted shorter sleep. Concurrently, THCCOOH concentration was associated with greater internalizing and externalizing symptoms.
Key Numbers
n=2,262 youth ages 9-15 (49% female); THC predicted more strength exercise; CBD predicted fewer exercise days; THCCOOH predicted shorter sleep duration; concurrent THCCOOH associated with greater internalizing and externalizing symptoms
How They Did This
Analysis of hair toxicology data from three cannabinoid analytes (THC, CBD, THCCOOH) and multiple health measures in the Adolescent Brain Cognitive Development (ABCD) Study. Two-part linear regression models assessed effects on externalizing/internalizing symptoms, exercise, asthma, and sleep. Stratified by sex with false discovery rate corrections.
Why This Research Matters
Hair analysis provides an objective measure of cannabis exposure over months, avoiding the limitations of self-report. Finding that different cannabinoids (THC vs CBD) have opposite associations with exercise, and that effects differ by sex, suggests cannabis exposure during adolescence has complex, sex-specific health implications.
The Bigger Picture
The ABCD Study is the largest long-term study of adolescent brain development in the US. These findings from objective hair biomarkers reinforce concerns about adolescent cannabis exposure while adding nuance that THC and CBD may have distinct and even opposing effects on health behaviors.
What This Study Doesn't Tell Us
Observational associations cannot establish causation; youth who use cannabis may differ from non-users in unmeasured ways. Hair cannabinoid levels may reflect environmental exposure (secondhand smoke), not just personal use. False discovery rate corrections were applied but multiple comparisons increase chance of spurious findings.
Questions This Raises
- ?Why did THC and CBD show opposite associations with exercise frequency?
- ?Are the sex differences in cannabinoid-health associations driven by biological differences in the endocannabinoid system or by gendered patterns of use?
Trust & Context
- Key Stat:
- THC and CBD showed opposite associations with exercise in adolescents
- Evidence Grade:
- Large nationally representative sample with objective biomarkers and prospective design provides moderate confidence, though observational design and potential for environmental exposure in hair samples are limitations.
- Study Age:
- 2025 publication from the ongoing ABCD Study
- Original Title:
- Cannabinoids in hair and their prospective association with mental and physical health outcomes in adolescents.
- Published In:
- Neurotoxicology and teratology, 108, 107433 (2025)
- Authors:
- Aks, Isabel R, Patel, Herry, Pelham, William E(3), Huestis, Marilyn A, Wade, Natasha E
- Database ID:
- RTHC-05887
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
Why use hair instead of urine or blood tests?
Hair analysis captures cannabinoid exposure over months rather than days, providing a longer-term picture of exposure. It also avoids reliance on self-report, which is especially unreliable in adolescents.
Did boys and girls show different effects?
Yes. Among males, THC and THCCOOH predicted shorter sleep duration. Among females, THC and THCCOOH predicted strength exercise frequency. These sex-specific patterns may reflect biological differences in how cannabinoids interact with the developing endocannabinoid system.
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Cite This Study
https://rethinkthc.com/research/RTHC-05887APA
Aks, Isabel R; Patel, Herry; Pelham, William E; Huestis, Marilyn A; Wade, Natasha E. (2025). Cannabinoids in hair and their prospective association with mental and physical health outcomes in adolescents.. Neurotoxicology and teratology, 108, 107433. https://doi.org/10.1016/j.ntt.2025.107433
MLA
Aks, Isabel R, et al. "Cannabinoids in hair and their prospective association with mental and physical health outcomes in adolescents.." Neurotoxicology and teratology, 2025. https://doi.org/10.1016/j.ntt.2025.107433
RethinkTHC
RethinkTHC Research Database. "Cannabinoids in hair and their prospective association with ..." RTHC-05887. Retrieved from https://rethinkthc.com/research/aks-2025-cannabinoids-in-hair-and
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.