Study: Marijuana potency increases in 2007

By HOPE YEN, Associated Press Writer 34 minutes ago

Marijuana potency increased last year to the highest level in more than 30

years, posing greater health risks to people who may view the drug as harmless,

according to a report released Thursday by the White House.

The latest analysis from the University of Mississippi's Potency Monitoring

Project tracked the average amount of THC, the psychoactive ingredient in

marijuana, in samples seized by law enforcement agencies from 1975 through

2007. It found that the average amount of THC reached 9.6 percent in 2007,

compared with 8.75 percent the previous year.

The 9.6 percent level represents more than a doubling of marijuana potency

since 1983, when it averaged just under 4 percent.

"Today's report makes it more important than ever that we get past outdated,

anachronistic views of marijuana," said John Walters, director of the White

House Office of National Drug Control Policy. He cited baby boomer parents who

might have misguided notions that the drug contains the weaker potency levels

of the 1970s.

"Marijuana potency has grown steeply over the past decade, with serious

implications in particular for young people," Walters said. He cited the risk

of psychological, cognitive and respiratory problems, and the potential for

users to become dependent on drugs such as cocaine and heroin.

While the drug's potency may be rising, marijuana users generally adjust to the

level of potency and smoke it accordingly, said Dr. Mitch Earleywine, who

teaches psychology at the State University of New York in Albany and serves as

an adviser for marijuana advocacy groups. "Stronger cannabis leads to less

inhaled smoke," he said.

The White House office attributed the increases in marijuana potency to

sophisticated growing techniques that drug traffickers are using at sites in

the United States and Canada.

A report from the office last month found that a teenager who has been

depressed in the past year was more than twice as likely to have used marijuana

than teenagers who have not reported being depressed 25 percent compared with

12 percent. The study said marijuana use increased the risk of developing

mental disorders by 40 percent.

"The increases in marijuana potency are of concern since they increase the

likelihood of acute toxicity, including mental impairment," said Dr. Nora

Volkow, director of the National Institute on Drug Abuse, which funded the

University of Mississippi study.

"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," Volkow said.

But there's no data showing that a higher potency in marijuana leads to more

addiction, Earleywine said, and marijuana's withdrawal symptoms are mild at

best. "Mild irritability, craving for marijuana and decreased appetite I mean

those are laughable when you talk about withdrawal from a drug. Caffeine is

worse."

The project analyzed data on 62,797 cannabis samples, 1,302 hashish samples,

and 468 hash oil samples obtained primarily from seizures by law enforcement

agencies in 48 states since 1975.