US drug policy officials have warned that the marijuana being sold in the United States is twice as potent as that being sold elsewhere. They said this increases the threat of severe mental issues in pot users..
The average level of THC -- marijuana's psychoactive ingredient -- in seized drug samples is 9.6 percent, compared to just under four percent in 1983, according to the Office of National Drug Control Policy.
And the highest THC level found in a sample of pot measured in recent months was an astounding 37.2 percent, according to the research from the University of Mississippi's 32-year-old Potency Monitoring Project.
"The increases in marijuana potency are of concern since they increase the likelihood of acute toxicity, including mental impairment," Nora Volkow, director of the US National Institute on Drug Abuse, said in a statement.
"Particularly worrisome is the possibility that the more potent THC might be more effective at triggering the changes in the brain that can lead to addiction; however, more research is needed to establish this link between higher THC potency and higher addiction risk," she said.
White House drug czar John Walters, the Director of National Drug Control Policy, warned that the higher potency make marijuana a greater health threat than in the past.
"Baby boomer parents who still think marijuana is a harmless substance need to look at the facts.
"Marijuana potency has grown steeply over the past decade, with serious implication in particular for young people, who may be not only at increased risk for various psychological conditions, cognitive deficits and respiratory problems, but are also at significantly higher risk for developing dependency on other drugs."