Heavy marijuana use causes poor memory and abnormal brain structure, study says

Teenagers who smoked marijuana daily for three years performed poorly on memory tasks and showed abnormal changes in brain structure, according to a Northwestern Medicine study.


Daily marijuana use has a measurable effect on the brain, a new study finds. Photo by Dean J. Koepfler/Tacoma News Tribune/MCT via Getty Images.

Teenagers who smoked marijuana daily for three years performed poorly on memory tasks and showed abnormal changes in brain structure, according to a Northwestern Medicine study.

Researchers in Chicago observed the memory-related structures in the users brains appear to shrink and collapse inward, which could indicate a decrease in neurons.

These abnormalities were recorded two years after the teens stopped using marijuana, possibly indicating long-term effects, and look similar to schizophrenia-related brain abnormalities.

The brains were shaped more abnormally for individuals who began marijuana use at a younger age, according to the reports, which suggest that memory regions of the brain are more susceptible to the drug at earlier ages.

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