The Washington Times - April 8, 2013, 01:53PM

Is marijuana a dangerous gateway drug or harmless diversion? The argument has gone on for years. A new, large scale study, however, suggests some alarming news.

“Individuals who use marijuana recreationally are more likely to misuse other drugs, including pain-controlling, but potentially addictive narcotics, sedatives and other prescription medications, than individuals who do not use marijuana,” says a new national study by Quest Diagnostics, the world’s largest medical testing lab.


The study also found that while marijuana was the most frequently abused drug of patients tested, individuals who used prescribed marijuana were not more likely to misuse other drugs than non-marijuana users.

The company’s conclusion goes right to the source: the study is based on an analysis of 227,402 de-identified urinelab-test results of patients, age 10 years and older, of both genders in 49 states and the District of Columbia performed by the company’s clinical laboratories in 2011-12. The results were part of the company’s prescription drug monitoring services that check for appropriate patient use of up to 26 commonly abused prescription medications, such as opioids and sedatives, and illicit drugs, such as marijuana and cocaine.

“This study provides important evidence that people who use marijuana have greater risk of other forms of drug misuse. Future research is needed to determine the exact nature of this relationship and to inform substance prevention efforts,” said Dr. Christian Thurstone, M.D., an assistant professor of psychiatry at the University of Colorado School of Medicine and medical director of Denver Health, an adolescent substance abuse program in Denver.

Quest will present additional findings at the 2013 American Academy of Pain Medicine in mid-April.