Heavy Marijuana Users Shrinking Their Brains

Not only does it appear that heavy marijuana users increase the chances of psychotic episodes, but that they shrink their brains.

Reporting in the Archives of General Psychiatry, researchers from the Universities of Melbourne and Wollongong tested 15 heavy marijuana users against 16 men who were not users. The users were aged 40 on average and had been smoking marijuana for about 20 years. They either smoked no less than 5 or 10 joints daily.

The conclusion? heavy smokers of marijuana had shrunk the hippocampus and the amygdala. The hippocampus regulates emotion and memory. The amygdala also are responsible for memory, fear and aggression.

Marijuana users also scored worse on verbal learning.

“These findings indicate that heavy daily cannabis use across protracted periods exerts harmful effects on brain tissue and mental health” according to the researchers.