Doctors confirm: smoking marijuana is not harmful to the brain
An international team of doctors from Australia, the United Kingdom and the United States evaluated the relationship between habitual cannabis exposure and gray matter volumes in seven brain regions, including:
- the thalamus,
- the hippocampus,
- amygdala e
- the nucleus accumbens
The researchers reported that “normal variation in cannabis use is not statistically related to individual differences in brain morphology as measured by subcortical volume.”
Doctors’ conclusions
“This is the largest exploratory analysis integrating brain imaging with self-report of cannabis and comorbid substance use data. After adjusting for multiple testing, there was no effect of cannabis use on volume in any subcortical region of interest.
In the context of increasing medicalization and decriminalization and concerns about the consequences of increased cannabis availability, our findings suggest that normal variation in cannabis use is not statistically related to brain morphology measured with subcortical volumes in non-clinical samples.“
The findings are in line with previous brain imaging studies. As they report that exposure to cannabis appears to have little to no negative impact on brain morphology. This is especially true when compared to the dramatic effects associated with alcohol exposure. Two weeks ago, a meta-analysis of 69 independent studies reported that cannabis exposure in adolescents and young adults is not associated with any significant residual negative effects on cognitive performance. Results from a pair of recently published longitudinal twin studies also report that cannabis use is not independently associated with any residual changes in intelligence quotient or executive function.