The frequent use of cannabis is not associated with changes in brain structure, according to data published online ahead of print in the journal Addiction. Authors reported, “[N]ormal variation in cannabis use is statistically unrelated to individual differences in brain morphology as measured by subcortical volume.”
Neither the occasional nor the heavy use of marijuana by adolescents is associated with decreased motivation, according to clinical data published online ahead of print in the journal Substance Use & Misuse. Authors reported: “After controlling for confounds, no significant differences were observed between regular and light users on any motivation index.”
Cannabis use by teens is not independently linked with adverse changes in intelligence quotient or executive functioning, according to longitudinal data published online ahead of print in the journal Addiction. Investigators concluded, “Short-term cannabis use in adolescence does not appear to cause IQ decline or impair executive functions, even when cannabis use reaches the level of dependence.”
Alcohol consumption is associated with negative changes in gray matter volume and in white matter integrity, while cannabis use is not, according to data published online ahead of print in the journal Addiction.
A recently released white paper published by the National District Attorneys Association is calling for the federal government to strictly enforce anti-cannabis laws in states that have regulated its production and distribution for either medical or recreational purposes.
NORML reviews the top news stories of 2015.
Two new studies published online today in JAMA (Journal of the American Medical Association) Psychiatry provide little support for previous claims that cannabis exposure is significantly harmful to the developing brain.
It was less than a year ago when the mainstream media was chock-full of headlines like this one: ‘Brain changes associated with casual marijuana use in young adults, study finds.’
But a funny thing happened when a team of scientists from the University of Colorado and the University of Kentucky tried to replicate these results in a separate, larger sample (158 participants) of subjects after rigorously controlling for both groups’ use of alcohol. They couldn’t.
NORML’s Deputy Director today on Alternet.org addressed new media claims that cannabis use can potentially shrink the brain.
Investigators at the University College of London analyzed data from 2,612 subjects who had their IQ tested at the age of eight and again at age 15. They reported no relationship between cannabis use and lower IQ at age 15 when confounding factors such as alcohol use and cigarette use were taken into account.