The Office of National Drug Control Policy (ONDCP) released a report Thursday (May 14) showing that levels of THC in marijuana are highest since the analysis of the drug began in the late 1970s.

According to the latest data on marijuana samples analyzed to date, the average amount of THC in seized samples has reached a new high of 10.1%. This compares to an average of just under 4% reported in 1983 and represents more than a doubling in the potency of the drug since that time.

According to the ONDCP, the University of Mississippi's marijuana Potency Monitoring Project has analyzed and compiled data on over 1,500 marijuana seizure specimens including cannabis, hashish, and hash oil samples confiscated by law enforcement agencies during 2008.

In its most recent Quarterly Report, the highest concentration of THC found in a marijuana sample during this period was 27.3%. In the analysis, over 40% of all specimens analyzed from 2008 were high potency, containing THC levels of 9% or greater. About three-fourths of the cannabis samples acquired were from law enforcement seizures, and the remaining were from domestic eradications.

The project has conducted an ongoing analysis of seized marijuana samples since 1976.

The following were some key facts from the report:

• An analysis of marijuana seizures at Southwest border ports-of-entry shows increasing levels of potency, from a median potency of 4.8% in 2003, to 5.2% in 2005, to 7.3% in 2007. This indicates increasing potency in marijuana is not only seen from expected domestic sources, such as indoor cultivation, but from traditionally low potency non-U.S. sources crossing the Southwest border.
• The latest Treatment Episode Data Set review of drug treatment admissions in the United States has shown that treatment admissions for marijuana as the primary substance of abuse has increased steadily from 198,000 people in 1997 to 288,000 in 2007. (SAMSHA)
• According to the NIDA, heavy marijuana use impairs a person's ability to form memories, recall events, and shift attention from one thing to another. THC also disrupts coordination and balance by binding to receptors in the cerebellum and basal ganglia, parts of the brain which regulate balance, posture, coordination of movement, and reaction time. Through its effects on the brain and body, marijuana intoxication can cause accidents.
• Other recent studies show marijuana use can be a risk factor for the onset of schizophrenia in vulnerable individuals, and may be associated with other mental disorders, including depression and anxiety.

Check out the full press release at WhiteHouseDrugPolicy.com.