By Steve Elliott
Marijuana use doesn't cause alterations in brain structure, according to a new study which fails to support past claims about cannabis and brain health.
The clinical data were published this week in JAMA Psychiatry, reports Paul Armentano at NORML.
Scientists looked at the effect of marijuana exposure on brain volume in the hippocampus, the amygdala, the ventral striatum, and the orbitofrontal cortex in groups of exposed and unexposed pairs of siblings. Researchers reported that all the volumetric differences identified "were within the range of normal variation," and that they were attributable to "shared genetic factors," not marijuana use.
"We found no evidence for the causal influence of cannabis exposure on amygdala volume," the authors concluded.
"We found that while cannabis users had lower amygdala volumes than nonusers, that difference appears to be linked to other predisposing factors," said senior author Arpana Agrawal, an associate professor of psychiatry at Washington University School of Medicine in St. Louis, reports Dennis Thompson at HealthDay