Marijuana Research Finds Shrunken Brains

From the Guardian.co.uk:

Smoking cannabis for long periods of time may shrink parts of the brain that govern memory, emotion and aggression, according to researchers in Australia. Scientists used magnetic resonance imaging to scan the brains of people who admitted to smoking more than five joints a day for at least 10 years and compared them with brain images taken from non-drug users.

Those who smoked cannabis regularly had on average a 12% smaller hippocampus, the part of the brain which is thought to be involved with emotion and memory, and a 7% smaller amygdala, which plays a role in regulating fear and aggression.

For the study, researchers imaged the brains of 15 cannabis smokers and 16 individuals who did not use the drug. The scientists, led by Murat Yücel at the University of Melbourne and colleagues at the University of Wollongong, said scans on larger numbers of people were needed to confirm the extent of the effect.

I met a heavy marijuana smoker years ago who couldn't remember the simplest things. I swear, it was like he had no short-term memory. Therefore, I'm inclined to give credence to the research even though it encompassed a small sample group.