August 2013 Regular cannabis use that starts in adolescence strips away IQ, a NIDA-supported study suggests. Participants who initiated weekly cannabis use before age 18 dropped IQ points in proportion to how long they persisted in using the drug. Persistent cannabis users’ cognitive difficulties were evident to friends and family and measurable on a battery of tests.
Illicit drug use in the United States in 2010 was at its highest level since 2002, according to the most recent report from the National Survey on Drug Use and Health. A rise in marijuana use drove the increase. A favorable trend of falling cocaine use continued.