ArticleBiological psychiatry2022
Diminished Structural Brain Integrity in Long-term Cannabis Users Reflects a History of Polysubstance Use.
Article in Biological psychiatry, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
9 citing papers in PubMed, 1 synthesis or guideline pooled it, 10 citations in OpenAlex.
- Measuring white matter microstructure in 1,457 cannabis users and 1,441 controls: A systematic review of diffusion-weighted MRI studies.Frontiers in neuroimaging · 2023Pooled it
- Alexithymia mediates white-matter microstructure and substance use escalation in trauma-exposed individuals.Journal of affective disorders · 2026Article
- Brain Structure and Substance Use: Disentangling Risk, Exposure, and Drug-Specific Effects.medRxiv : the preprint server for health sciences · 2026Article
- Young Adult Substance Use as a Predictor of Poor Self-Rated Memory Decades Later in Midlife.Journal of aging and health · 2026Article
- Resilience and Brain Changes in Long-Term Ayahuasca Users: Insights From Psychometric and fMRI Pattern Recognition.Journal of magnetic resonance imaging : JMRI · 2025Article
- DNA methylation profiles of long-term cannabis users in midlife: a comprehensive evaluation of published cannabis-associated methylation markers in a representative cohort.Molecular psychiatry · 2025Article
- Association Between Cannabis Use and Brain Structures: A Mendelian Randomization Study.Cureus · 2024Article
- Childhood blood-lead level predicts lower general, non-selective hippocampal subfield volumes in midlife.Ecotoxicology and environmental safety · 2024Article
- Polysubstance Use Plays a Key Role in Midlife Structural Brain Alterations in Long-term Cannabis Users.Biological psychiatry · 2022Article
Corrections and comments
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Authors and funding
11 authors at 4 institutions in 3 countries.
Funding
Abstract
backgroundCannabis legalization and use are outpacing our understanding of its long-term effects on brain and behavior, which is fundamental for effective policy and health practices. Existing studies are limited by small samples, cross-sectional measures, failure to separate long-term from recreational use, and inadequate control for other substance use. Here, we address these limitations by determining the structural brain integrity of long-term cannabis users in the Dunedin Study, a longitudinal investigation of a population-representative birth cohort followed to midlife.
methodsWe leveraged prospective measures of cannabis, alcohol, tobacco, and other illicit drug use in addition to structural neuroimaging in 875 study members at age 45 to test for differences in both global and regional gray and white matter integrity between long-term cannabis users and lifelong nonusers. We additionally tested for dose-response associations between continuous measures of cannabis use and brain structure, including careful adjustments for use of other substances.
resultsLong-term cannabis users had a thinner cortex, smaller subcortical gray matter volumes, and higher machine learning-predicted brain age than nonusers. However, these differences in structural brain integrity were explained by the propensity of long-term cannabis users to engage in polysubstance use, especially with alcohol and tobacco.
conclusionsThese findings suggest that diminished midlife structural brain integrity in long-term cannabis users reflects a broader pattern of polysubstance use, underlining the importance of understanding comorbid substance use in efforts to curb the negative effects of cannabis on brain and behavior as well as establish more effective policy and health practices.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.