Marijuana & Memory Loss
A new study at Northwestern University has found that teens who were heavy marijuana users--smoking most days for 3 years or more--had abnormal brain structures, and performed poorly on short term memory tests. Those problems persisted at least 2 years after marijuana usage stopped, a possible indicator of long term effects.
Memory related brain structures appeared to shrink and collapse inward, possibly reflecting a decrease in neurons. The younger these teenagers were when they started using marijuana, the more abnormally their brain regions were shaped.
Some of those changes in brain structure may be associated with schizophrenia. Results of this study were published in the December 16 issue of the journal Schizophrenia Bulletin.
Marijuana is the most commonly used illegal drug in the US, and young adults have the highest use.