OXFORD, Miss. – Marijuana confiscated in the United States is more
potent than ever before, according to a news release
yesterday from the Office of National Drug Control Policy.
The average amount of tetrahydrocannabinol, or THC, marijuana’s
psychoactive ingredient, has reached a new high of 10.1 percent. The
average reported in 1983 was just under 4 percent, so today’s pot, on
average, is more than twice as potent as it was two-and-a-half decades
ago.
The ONDCP release is based on data in the most recent quarterly report
from the University of Mississippi’s Potency Monitoring Project, which
has been analyzing samples of marijuana, hashish and hash oil seized in
the U.S. since 1976. The project is funded by the National Institute on
Drug Abuse.
As of March 15, the PM Project analyzed and compiled data on 1,500
samples of products derived from Cannabis sativa that were seized by
law enforcement agencies during 2008. These 1,500 samples represent
about three-fourths of all the samples analyzed by the UM laboratory.
The remaining samples were from domestic eradications.
According to the project’s report, more than 40 percent of all samples
analyzed from 2008 were high potency, containing THC levels of 9
percent or greater. The highest concentration of THC found in a
marijuana sample during the report period was 27.3 percent.
The highest concentration of THC ever found in a marijuana sample was
37.2 percent. The sample came from a batch of marijuana seized in
California in September 2007.
“Some of the samples we test contain a THC content of more than 30 percent,” said Mahmoud ElSohly, director of the NIDA Marijuana Project in the UM School of Pharmacy.
Although ElSohly expects average THC levels to continue to rise, he believes they will top off at 15-16 percent due to the genetic limitations of Cannabis plants.
Additional Key Facts
Marijuana seized at Southwest border ports-of-entry is becoming more potent, with analyses revealing a median THC concentration of 4.8 percent in 2003, 5.2 percent in 2005 and 7.3 percent in 2007.
“Traditionally, marijuana coming into the country across the Southwest border has been low potency,” said ElSohly. “But that marijuana also is becoming more potent, as is marijuana from domestic sources, such as indoor growing operations.”
A review of the latest Treatment Episode Data Set reveals that drug treatment admissions for marijuana as the primary substance of abuse have increased steadily in the United States, rising from 198,000 people in 1997 to 288,000 in 2007.
According to the NIDA’s fact sheet on marijuana , 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 that regulate balance, posture, coordination and reaction time.
It is these effects on the brain and body that can cause accidents, with studies showing that approximately 6 percent to 11 percent of fatal accident victims test positive for THC, says NIDA’s fact sheet on drugged driving. In many of these cases, alcohol is detected as well.
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 (Moore, et al., Lancet 2007; 370:319-328).
For more information about the Office of National Control Policy, visit http://www.ondcp.gov . For more information about the National Institute on Drug Abuse, visit http://www.nida.nih.gov .