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Testing associations between cannabis use and subcortical volumes in two large population-based samples
Nathan A Gillespie1,2, Michael C Neale1, Timothy C Bates3
1Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, VA, USA.
Addiction (Abingdon, England)
|April 26, 2018
Summary
This study found that cannabis use does not significantly impact subcortical brain volumes in adults. Nicotine use, however, was linked to smaller thalamus volumes in middle-aged males.
Area of Science:
- Neuroscience
- Brain Imaging
- Substance Use Research
Background:
- Cannabis's effects on brain structure are debated.
- Comorbid substance use complicates research on cannabis's neurological impact.
- Understanding cannabis's independent effect on brain morphology is crucial.
Purpose of the Study:
- To investigate the association between frequent cannabis use and subcortical grey matter volumes.
- To control for the influence of nicotine, alcohol, and multi-substance use.
- To determine if cannabis use independently affects brain morphology.
Main Methods:
- Utilized mixed linear models to analyze brain volumes in seven subcortical regions.
- Employed magnetic resonance imaging (MRI) and volumetric segmentation.
- Included two large population-based twin samples from the US and Australia.
Main Results:
- Cannabis use was not statistically related to any subcortical region of interest (ROI) after multiple testing correction.
- Nicotine use was associated with significantly smaller thalamus volumes in middle-aged males.
- No significant association was found between cannabis use and subcortical brain volumes.
Conclusions:
- Normal variation in cannabis use is not statistically linked to individual differences in subcortical brain volumes.
- Findings suggest cannabis use, in isolation, may not alter brain morphology.
- Nicotine use presents a potential risk factor for reduced thalamus volume.
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