Addiction

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It didn't take 3,000 years and a $4 million dollar study to know Atrophy of the brain and cirrhosis of the liver are long-term side effects of heavy alcohol dependence. And withdrawal for alcoholics can bring sometimes fatal delirium tremors and convulsions.

Study aims to clear haze surrounding pot addiction

By Terri Somers
UNION-TRIBUNE STAFF WRITER
The San Diego Union-Tribune
March 14, 2008

Atrophy of the brain and cirrhosis of the liver are long-term side effects of heavy alcohol dependence. And withdrawal for alcoholics can bring sometimes fatal delirium tremors and convulsions.

Those facts are well known.

But much less is known about marijuana, the nation's most widely used and socially accepted illicit drug. Our knowledge of marijuana is often based on personal experience, observation or anecdotes, despite a growing collection of scientific studies on the topic.

<table class=posttable align=right width=140><tr><td class=postcell><img class=postimg src=bin/mason_barbara.jpg></td></tr></table>Scripps Research Institute addiction expert Barbara Mason hopes to change that, and to help find novel treatments for addiction to marijuana, with some solid scientific data.

Mason is leading the first-ever comprehensive study on the neurobiological effects of cannabis addiction, funded with a $4 million grant from the National Institute on Drug Abuse.

The four-year project will involve animal and human studies that look at what happens in the body during cannabis addiction. That data will then be compared to what happens in the body during withdrawal and afterward.

The four scientific labs involved, including one at UCSD, will then submit their findings to the drug abuse institute to help researchers develop new medications that can help prevent relapse.

Not that Mason wants to be a buzz kill.

“I'm not a stand-on-the-soapbox kind of person,” Mason said. “I just feel like there's a real gap in our knowledge and understanding of cannabis that I want to fill in.”

She has spent two decades researching addiction, withdrawal and treatment. She is the director of Scripp's Laboratory of Clinical Psychopharmacology. And she has won national honors for her groundbreaking work on the combination of alcohol and depression, as well as her research into medical therapies to treat withdrawal from alcohol dependence.

Dr. Mark Gold, chairman of the psychology department at the University of Florida, said Mason is a world class investigator and the study is significant.

“Cannabis addiction is a common patient complaint,” he said. “While treatments have been developed for addictions from alcohol to nicotine and narcotics, none exists for the cannabis dependent. This research will help the field define what cannabis is and is not, and how to treat it.”

Studies at the University of Michigan in 1994 and 2004 show that one in every nine or 10 people who tries marijuana becomes dependent.

In the commonly used medical reference manual for psychiatric disorders, there is precise information about intoxication, dependence and withdrawal from substances ranging from alcohol to nicotine to heroin. But there is no information on cannabis.

And if it isn't listed in the manual, it doesn't exist in the treatment world and, perhaps more importantly, in the eyes of health insurance companies, said Dr. Ivan Montoya, who is with the NIDA's division of pharmacotherapies and medical consequences of drug abuse.

Mason said there is proof in animal and human studies of a withdrawal syndrome for cannabis. Like with nicotine, relapsing with marijuana gets rid of the symptoms, she said.

Two of the most frequent, long-lasting symptoms seen in people trying to stop smoking marijuana are sleep disturbances, such as vivid bad dreams, and negative behavioral affects, such as anxiety, anger and irritability, she said.

The symptoms are more subtle than withdrawal from other substances, such as alcohol. But alcohol clears from the system in a couple of days, she said.

Part of the problem with marijuana is its long half-life. Because it can be detected in a person's body 30 days after the last use, withdrawal symptoms can last at least that long, Mason said.

And other addiction treatment specialists point out that marijuana lingers indefinitely in some human tissue. So how long does the drug affect someone's physical functions and thought process?

An objective of Mason's work will be to study all the manifestations of the withdrawal, including stress hormones that are released, subjective effects reported by the patients and the effect on sleep and mood.

The study will research the effect marijuana has at different stages on development, comparing teens between the ages of 15 through 18, whose brains are still developing, and young adults ages 21 through 30.

The research will investigate how cannabis affects the capacity for learning, as well as the ability to make judgments and control impulses, which are cognitive processes that are needed for treatment, she said.

The study will involve neurophysiological testing and functional imaging of the brain, to determine how long the effects last, Mason said.

The project will also be able to take advantage of what Montoya said have been tremendous advances in the science of marijuana in recent years, including the presence of receptors in the brain that react to it.

“The thing that troubles a lot of us is that (marijuana) has such an appeal to younger people, and in recent time we have learned that the adolescent brain is so different in many ways that the final adult version,” said Dr. Reese Jones, a psychiatry professor at the University of San Francisco. “There is a lot of reason to think that all these issues may be a bigger deal in younger people.”

Recruitment for the study will be conducted through advertising and a Web site. Mason does not expect difficulty finding participants.

She is currently running a separate, more narrow study on treatment for cannabis addiction. When preparing to recruit participants for it, Mason said she worried she was “throwing a party that no one wanted to attend.”

The response surprised her.

“I've been doing alcohol research for a long time, and I got more people seeking treatment for cannabis than I did for alcohol,” she said.

About one-third of those don't use anything but cannabis, she said. And there were two predominant age groups, college-aged and people in their mid-50s, she said.

Southern California is a great location for the study, because there is confusion about the drug, she said. Medical marijuana, though illegal under federal law, is legal in the state.

“I think, in part, that's because policy has been made based on personal biases, rumor and innuendo, instead of science,” she said.


Terri Somers: (619) 293-2028; terri.somers@uniontrib.com