Before pot vote, consider health impact

With California voters set to decide in November whether to legalize marijuana, Los Angeles County’s top health officer has come up with an analysis of the drug’s effects.

Dr. Jonathan E. Fielding’s June 8 report to the Los Angeles County Board of Supervisors draws on an array of studies from authorities, including the American Medical Assn. to examine what marijuana does to the health of those who use it medically or recreationally.

“We really tried to be very objective,” said Fielding, the county’s director of public health. He said he was moved to create the report because of a shortage of comprehensive data on the subject.

“There’s a lot of mythology on all sides here,” he said in an interview. “Trying to understand what the science says is often a good first step.”

Fielding’s analysis does not come down on either side of the initiative, but includes statistics about how often marijuana use is a factor in some treatment and hospital settings.

One-third of those admitted to Los Angeles County substance abuse treatment facilities say that marijuana is their primary or secondary drug of choice, the report said. Nationwide, it contributed to 375,000 emergency room visits in 2008.

“Marijuana is a significant public health problem,” Fielding said.

Used medically, though, it may be effective in treating a few conditions, the report found. In addition to treating nerve pain, it also can help combat severe weight loss, alleviate some multiple sclerosis symptoms, fight chemotherapy-related nausea and vomiting and relieve eye pressure from glaucoma.

As for recreational use, Fielding’s report states that marijuana is consistently associated with difficulties in learning and remembering new information, along with lower test scores and decreased levels of academic achievement. Studies also have found that marijuana use correlates to increased consumption of other drugs. But it has not been “consistently associated with other measures of mental and psychological harm,” the report said.

The report, citing national surveys, says that more than 30% of people 18 and older who’ve used marijuana in the past year are classified as dependent on the drug. But that number is greatly reduced when actual “diagnostic criteria” for substance dependence are considered. Under that measure, between 4% and 9% of marijuana users are addicted. Overall, Fielding reported, marijuana users are “considerably less likely to [become dependent] than users of alcohol and nicotine, and withdrawal symptoms are less severe.” Still, younger users face higher risks, with 17% of those who’ve used the drug at age 13 becoming addicted.

Other findings:

• One recent clinical trial involving marijuana smokers had to be halted early when some participants started having suicidal thoughts.

• Marijuana’s association with psychosis is “somewhat controversial.” Although some recent studies suggest an increased psychosis risk associated with marijuana use, “marijuana accounts for only a small proportion of psychoses.”

• Smoking marijuana, like smoking tobacco, has been linked to lung damage and chronic bronchitis. Additional long-term studies are needed to determine whether marijuana smoking leads to an increased risk of lung cancer or other cancers of the oral cavity and airway.

The initiative to legalize, regulate and tax marijuana will appear on California’s November 2 ballot. It would allow people over 21 to grow and possess the drug and would permit local government to regulate and tax its sale. It would prohibit using marijuana in public or when minors are present, and would not allow its possession on school grounds,

Posted 6/22/10