Adolescents using methamphetamine and cannabis showed enlarged brain reward regions and higher novelty seeking
Adolescent methamphetamine and cannabis co-users had increased striatal brain volume and intensified novelty-seeking behavior compared to healthy controls.
Quick Facts
What This Study Found
Researchers compared brain scans from three groups of adolescents: healthy controls (10), methamphetamine users (9), and combined methamphetamine plus cannabis users (8). The combined Meth+cannabis group showed increased regional striatal volume and intensified novelty seeking compared to controls.
The degree of methamphetamine exposure correlated positively with both striatal volume and novelty seeking in both drug-using groups. The striatum is a brain region central to reward processing and motivation.
The findings supported theories that the striatum plays a key role in adolescent substance abuse vulnerability, and that drug use during adolescence may further modify this brain region while it is still developing.
Key Numbers
Controls: n=10. Meth only: n=9. Meth+cannabis: n=8. Meth exposure positively correlated with striatal volume and novelty seeking in both drug-using groups.
How They Did This
Cross-sectional neuroimaging study using 3T MRI. Three groups of adolescents: controls (n=10), methamphetamine users (n=9), methamphetamine+cannabis users (n=8). Structural brain imaging analyzed for regional striatal morphology. Novelty seeking assessed with Cloninger's Tridimensional Character Inventory.
Why This Research Matters
The striatum undergoes significant remodeling during adolescence. If substance use during this period enlarges or alters striatal structure, it could create a feedback loop where drug use increases reward sensitivity, which in turn increases drug-seeking behavior.
The Bigger Picture
This study could not determine whether enlarged striata predisposed adolescents to drug use or resulted from it. Both directions are plausible: pre-existing differences in reward circuitry may increase vulnerability, and drug use may further alter the developing brain.
What This Study Doesn't Tell Us
Very small sample sizes. Cross-sectional design cannot establish causation or temporal sequence. Cannot separate methamphetamine effects from cannabis effects in the co-use group. No longitudinal follow-up. Demographic differences between groups could confound results.
Questions This Raises
- ?Are striatal volume increases a cause or consequence of substance use?
- ?Does cannabis add to methamphetamine's effects on the striatum, or are these independent?
- ?Would striatal changes normalize with sustained abstinence?
Trust & Context
- Key Stat:
- Methamphetamine exposure correlated with both striatal volume and novelty seeking
- Evidence Grade:
- Cross-sectional neuroimaging study with very small groups. Preliminary findings that cannot establish causal direction.
- Study Age:
- Published in 2012. Adolescent brain development and substance use effects remain active areas of neuroimaging research.
- Original Title:
- Abnormal striatal circuitry and intensified novelty seeking among adolescents who abuse methamphetamine and cannabis.
- Published In:
- Developmental neuroscience, 34(4), 310-7 (2012)
- Authors:
- Churchwell, John C, Carey, Paul D, Ferrett, Helen L, Stein, Dan J, Yurgelun-Todd, Deborah A
- Database ID:
- RTHC-00550
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does drug use change the teen brain?
This study found structural differences in the brain's reward system (striatum) in drug-using adolescents. However, it could not determine whether the differences existed before drug use began or resulted from it. Both possibilities have implications for prevention and treatment.
What is novelty seeking and why does it matter?
Novelty seeking is a personality trait characterized by a strong drive to explore new experiences. Higher novelty seeking is associated with greater risk for substance use. In this study, drug-using adolescents showed intensified novelty seeking, potentially creating a cycle of increased reward-seeking behavior.
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Cite This Study
https://rethinkthc.com/research/RTHC-00550APA
Churchwell, John C; Carey, Paul D; Ferrett, Helen L; Stein, Dan J; Yurgelun-Todd, Deborah A. (2012). Abnormal striatal circuitry and intensified novelty seeking among adolescents who abuse methamphetamine and cannabis.. Developmental neuroscience, 34(4), 310-7. https://doi.org/10.1159/000337724
MLA
Churchwell, John C, et al. "Abnormal striatal circuitry and intensified novelty seeking among adolescents who abuse methamphetamine and cannabis.." Developmental neuroscience, 2012. https://doi.org/10.1159/000337724
RethinkTHC
RethinkTHC Research Database. "Abnormal striatal circuitry and intensified novelty seeking ..." RTHC-00550. Retrieved from https://rethinkthc.com/research/churchwell-2012-abnormal-striatal-circuitry-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.