How Cannabis and Alcohol Affect the Developing Adolescent Brain
Neuroimaging shows cannabis and alcohol use during adolescence alters brain structure and function, with some cognitive deficits resolving after short-term abstinence while attentional deficits persist.
Quick Facts
What This Study Found
This review examined how cannabis and alcohol affect the adolescent brain during a period when white and grey matter are still maturing and sex hormones are driving structural changes.
Neuroimaging studies revealed differences in brain development between substance-using and non-using adolescents, including altered white matter myelination and grey matter volumes. The effects appeared related to the ongoing developmental processes that cannabis and alcohol disrupt.
An important distinction emerged: some associations between substance use and brain differences appeared to resolve after short-term abstinence, suggesting they may be temporary pharmacological effects. However, attentional deficits appeared to persist even after abstinence, suggesting more lasting impact on attention-related brain circuitry.
The review also noted sexually dimorphic features in brain development, suggesting that cannabis and alcohol may affect male and female adolescent brains differently.
Key Numbers
The review synthesizes neuroimaging and neuropsychological data but does not report pooled statistics.
How They Did This
Review of neuropsychological and neuroimaging studies examining the effects of cannabis and alcohol on adolescent brain development, including structural MRI, functional MRI, and neurocognitive assessment data.
Why This Research Matters
Understanding which effects are temporary versus persistent helps prioritize prevention messages and guide clinical decisions. The finding that attentional deficits persist while other deficits may resolve suggests attention systems are particularly vulnerable during adolescent development.
The Bigger Picture
Adolescence is a critical neurodevelopmental window with ongoing myelination and synaptic pruning. The persistence of attentional deficits suggests that cannabis and alcohol may disrupt specific developmental processes that cannot be fully recovered even after discontinuation.
What This Study Doesn't Tell Us
Review does not present systematic methodology or quality assessment. Most neuroimaging studies are cross-sectional, making it difficult to separate pre-existing differences from substance-caused changes. The combined review of cannabis and alcohol may obscure substance-specific effects.
Questions This Raises
- ?Do the persistent attentional deficits eventually resolve with longer abstinence?
- ?Are there critical sub-periods within adolescence where exposure is most damaging?
- ?Would CBD-only exposure show the same effects as THC-containing cannabis?
Trust & Context
- Key Stat:
- Attentional deficits persisted after abstinence while other cognitive effects resolved
- Evidence Grade:
- Narrative review of neuroimaging and neuropsychological evidence. Moderate because it synthesizes substantial imaging data but lacks systematic methodology.
- Study Age:
- Published in 2017.
- Original Title:
- Cannabis and alcohol use, and the developing brain.
- Published In:
- Behavioural brain research, 325(Pt A), 44-50 (2017)
- Authors:
- Meruelo, A D, Castro, N(2), Cota, C I, Tapert, S F
- Database ID:
- RTHC-01456
Evidence Hierarchy
Summarizes existing research on a topic.
What do these levels mean? →Frequently Asked Questions
Can the teen brain recover from cannabis use?
This review found that some cognitive effects resolve after short-term abstinence, suggesting partial recovery. However, attentional deficits appeared to persist, suggesting some brain changes may be more lasting.
Does cannabis affect male and female teen brains differently?
The review notes sexually dimorphic features in adolescent brain development, suggesting cannabis and alcohol may affect male and female brains differently, though the specific differences require further study.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-01456APA
Meruelo, A D; Castro, N; Cota, C I; Tapert, S F. (2017). Cannabis and alcohol use, and the developing brain.. Behavioural brain research, 325(Pt A), 44-50. https://doi.org/10.1016/j.bbr.2017.02.025
MLA
Meruelo, A D, et al. "Cannabis and alcohol use, and the developing brain.." Behavioural brain research, 2017. https://doi.org/10.1016/j.bbr.2017.02.025
RethinkTHC
RethinkTHC Research Database. "Cannabis and alcohol use, and the developing brain." RTHC-01456. Retrieved from https://rethinkthc.com/research/meruelo-2017-cannabis-and-alcohol-use
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.