WA Today: January 5, 2012

A study published in the American Journal of Epidemiology has found that “occasional” cannabis use or “other light illicit drug use” may not be the cause of reduced “mental functioning”, however heavy, ongoing use of drugs was linked with a decline in function. Almost 9000 people in Britain had their mental function and memory tested at the age of 50 as part of the study. People who had used illicit drugs “as recently as in their 40s did just as well, or slightly better, on the tests than peers who had never used drugs.” However as is pointed out by John Halpern, a psychiatrist at Harvard Medical School, this finding may simply “reflect another finding – that people who’d ever used drugs generally had a higher education level than non-users.” Cannabis was the most commonly reported drug used by participants.