STUDY: POT DOESN'T HURT THINKING SKILLS

Recreational Use Appraised

Marijuana does not substantially harm thinking skills of long-term
recreational users, according to researchers at the University of
California San Diego.

They analyzed 15 previously published research studies, and the only side
effect found was a minimal reduction in learning and memory.

"In the case of cannabis, there is a back-and-forth in literature about
brain damage," said Igor Grant, M.D., the study's senior author and
director of UCSD's Center for Medicinal Cannabis Research. "We found that
marijuana users were surprisingly intact."

UCSD researchers evaluated the neurocognitive abilities of 704 cannabis
users and 484 nonusers. In addition to learning and memory, UCSD
researchers looked at participants' simple reaction time, attention and
motor and language skills.

While the studies included a wide range of marijuana users, Grant defined
recreational marijuana users as those who smoke a couple of times a month
to a couple of times a week.

The marijuana group was slightly more likely to have minor memory problems,
said Grant, who is also a professor of psychiatry at UCSD.

It's unlikely that the problems identified in the lab would significantly
affect the users in the real world, he said.

The study will be published today in the July issue of the Journal of the
International Neuropsychological Society.

UCSD's Center for Medicinal Cannabis Research is a state-supported program
between UCSD and UC San Francisco that oversees studies of medicinal cannabis.

Grant emphasized that only marijuana's residual effects on the brain were
studied, not the short-term effects of a marijuana high.

He called the analysis' conclusions "curious."

"You would expect that a group of heavy marijuana users would have more
difficulties," he said.

From a neurological standpoint, the analysis suggests that there is a fair
amount of safety in short-term medicinal marijuana use, Grant said.

In 1996, California voters adopted Proposition 215, which permits the
seriously ill to use marijuana for medicinal purposes. A Medical
Marijuana/Cannabis Task Force was created to help advise the San Diego City
Council on regulating medicinal marijuana.

"It's one more factor for policy-makers to look at and consider," said Ed
Plank, a task force member. "This will be one more piece of information to
help weigh the potential negative impacts versus the benefits."

The task force is searching for $35,000 in funding to begin a new medicinal
marijuana program. The City Council approved the Voluntary Verification
Card Program last year. It will allow people with a card to legally possess
up to 1 ounce of marijuana.

Humbolt County, Marin County and the city of San Francisco have active
verification card programs.

Marijuana use, however, remains against federal law.

"I don't think people should read into the results (of the study,)" Grant
said. "The study was not designed to address issues of legalization of
marijuana or whether it's appropriate to use recreationally."

Grant noted that there were significant limitations in the researchers'
evaluation.

Complications in the individual studies, such as lingering traces of
marijuana in the body and the accuracy of the subjects' self-reporting,
posed problems. It was also possible that the participants in the studies
used other drugs.

Despite the specific focus of the evaluation, Grant said he knows that
people will interpret the study to their liking.

"I'm sure people will spin this in various ways," he said.

Jenny Diamond is a Union-Tribune intern.