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Press Release

April 25, 2007
ONDCP Public Affairs: (202) 395–6618

Study Finds Highest Levels of THC in U.S. Marijuana To Date

20 Year Analysis of Marijuana Seizures Reveals a Doubling in Pot Potency Since Mid-80's;

New Strains of Marijuana May Be Behind Increase in Teen Marijuana Treatment Admissions and Rise in Emergency Room Episodes Related to Marijuana

White House Drug Czar Warns: "This isn't your father's marijuana."

(Washington, D.C.)—Today, the Office of National Drug Control Policy (ONDCP) and the National Institute on Drug Abuse (NIDA) released the latest analysis from the University of Mississippi's Potency Monitoring Project which revealed that levels of THC—the psychoactive ingredient in marijuana—have reached the highest-ever levels since scientific analysis of the drug began in the late 1970's. According to the latest data on marijuana samples analyzed to date, the average amount of THC in seized samples has reached 8.5 percent. This compares to an average of just under 4 percent reported in 1983 and represents more than a doubling in the potency of the drug since that time.

As of March 15, 2007, the University of Mississippi has analyzed and compiled data on 59,369 cannabis samples, 1,225 hashish samples, and 443 hash oil samples confiscated by law enforcement agencies since 1975. In its most recent quarterly Report, the highest concentration of THC found in a marijuana sample during this period was 32.3 percent. Two-thirds of the cannabis samples seized in 2006 were from law enforcement seizures and purchases, and the remaining were from domestic eradications. The law enforcement seizures were obtained from 45 different states. The Potency Monitoring Project is funded through by the National Institute on Drug Abuse and has conducted an ongoing analysis of seized marijuana samples since 1976.

John Walters, Director of National Drug Control Policy and President Bush's "Drug Czar" expressed serious concerns regarding this trend, "This new report serves as a wake-up call for parents who may still hold outdated notions about the harms of marijuana. Evidence now tells us that the higher-than-ever potency of today's marijuana translates into serious health consequences for teens. Among teens who are receiving treatment for drug abuse or dependence, more than 60% report marijuana as their primary drug of abuse. Additionally, we are now seeing more mentions of marijuana during visits to emergency rooms than ever before. A growing body of research now tells us that marijuana poses a serious threat to the health and futures of young people. Parents need to start having critical conversations with their children about this drug."

Dr. Nora Volkow, Director of NIDA stated, "Although the overall number of young people using marijuana has declined in recent years, there is still reason for great concern, particularly since roughly 60 percent of first-time marijuana users are under 18 years old. During adolescence and into young adulthood, the brain continues to develop and may be vulnerable to marijuana's deleterious effects. Science has shown that marijuana can produce adverse physical, mental, emotional, and behavioral changes, and—contrary to popular belief—it can be addictive."

Higher potency marijuana may be contributing to a substantial increase in the number of American teenagers seeking treatment for marijuana dependence. According to the National Survey on Drug Use and Health (NSDUH), of the 15.1 million current (past-month) users, 4.1 million Americans (1.7 percent) report dependency or abuse of marijuana. Additionally, the latest information from the Treatment Episode Data Set (TEDS, 2005), reports that 20.1% of drug treatment admissions were for marijuana as the primary drug of abuse. This compares to 6% in 1992.

The increasing strength of marijuana may also be linked to increasing mentions of marijuana in hospital emergency rooms. The Drug Abuse Warning Network (DAWN), a national surveillance system that monitors trends in drug-related emergency department visits and deaths, and is operated by the Substance Abuse and Mental Health Services Administration (SAMHSA), has found that DAWN emergency room mentions of marijuana have increased nationally from 45,000 in 1995 to 119,000 in 2002 (Data since 2002 cannot be compared with earlier years).

Seizure Specimen Potency Trend

Source: Univ of Mississippi Marijuana Potency Monitoring Project, Report 95, Jan 9 2007 <Click here for larger image>

Potency of All Tested Cannabis Specimens

Source: Univ of Mississippi Marijuana Potency Monitoring Project, Report 95, Jan 9 2007 <Click here for larger image>

Last Updated: May 1, 2007

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