22 Jan Study finds marijuana has no effect on teen brain tissue, unlike alcohol use
Researchers at UC San Diego and the University of Pittsburgh announced the results of a study that regular marijuana use doesn’t damage brain tissue, while routine drinking does.
The brains of 92 young people — ages 16 to 20 — were scanned by UC San Diego researchers over 18 months. The participants with histories of alcohol and marijuana use, about half, continued using. The other half abstained or maintained minimal use. The study observed physical brain tissue, not overall performance of the participants.
The before-and-after scans showed that teens drinking at least 5 drinks per week had reduced brain tissue health — possibly leading to declines in attention span, memory and decision-making. The brain tissue of teens who used only marijuana up to 9 times per week showed no physical damage.
“If teens decrease their tissue health and cognitive ability to inhibit themselves, they might become more likely to engage in risky behavior like excessive substance use.”JOANNA JACOBUS, UC SAN DIEGO
Alcohol use “becomes a cycle,” Jacobus said, because teens who drink regularly damage areas of the brain that influence self-control and judgment. She said marijuana may not be as harmful in part because different strains of the plant have varying intensities and some “may actually have neuroprotective effects.”
Researchers couldn’t definitively say why alcohol was damaging while marijuana was not and cautioned that more research was needed. They also couldn’t say if the damaged brain tissue was permanent. The study will be published in the journal “Alcoholism: Clinical & Experimental Research.”
The National Institutes of Health (NIH) released results of a survey Dec. 18 that showed nearly 23% of 12th graders said they had smoked marijuana in the last month.
Source: Cir