News Tip: Teen Pot Use Up -- May Cause Lasting IQ Loss

The Monitoring the Future Report, released by the National Institute on Drug Abuse Wednesday morning, has found that 6.5 percent of U.S. high school seniors smoke marijuana daily, up from 5.1 percent five years ago. Nearly 23 percent say they smoked it in the month prior to the survey, and just over 36 percent say they smoked within the previous year.A Duke researcher led an analysis of long-term data that tracked nearly 1,000 New Zealanders from birth to middle age and found a significant loss in IQ among adults who had used marijuana regularly during adolescence. The loss is not reversed by quitting pot later. Madeline MeierPost-doctoral researcher in the Duke University Center for Child and Family Policymh214@duke.edu Quote:"Continued high use of marijuana among today's teens increases concerns about the potential public health impact of marijuana on teen's brains. Our recent study suggested that adolescents who use marijuana and use it persistently experience an 8-point IQ decline. With more teens using marijuana today than when our study occurred, our concern is that a growing proportion of the population will be affected. "Marijuana is not harmless, particularly for adolescents. Somebody who loses 8 IQ points as an adolescent may be disadvantaged compared to their same-age peers for years to come."CITATION: "Persistent Cannabis Users Show Neuropsychological Decline From Childhood to Midlife," Madeline H. Meier, Avshalom Caspi, et al. Proceedings of the National Academy of Sciences, Online Early Edition, Monday, Aug. 27, 2012. DOI:10.1073/pnas.1206820109