UW News

April 13, 2016

UW study aimed at users of both marijuana and tobacco

News and Information

If you’re looking to give up marijuana and possibly cigarettes as well, a group of researchers at the University of Washington would like to hear from you.

The Innovative Programs Research Group, an organization in the UW School of Social Work, is recruiting people 18 and older for a free marijuana and tobacco treatment trial. The study is aimed at adults who are regularly using both substances, want to quit marijuana and are willing to consider kicking the tobacco habit as well.

This group tends to struggle when it comes to quitting marijuana. Rates of tobacco use are high among regular cannabis users — between 40 and 90 percent, depending on the study and the population — and people who seek treatment for marijuana use who are also smokers tend to have poorer outcomes and higher relapse rates, principal investigator Denise Walker said.

“We have some indication that people coming into treatment using both tobacco and pot don’t do as well in treatment as folks who only use marijuana, so how do we better help them?” said Walker, director of the Innovative Programs Research Group. “If we also focus on tobacco smoking while they’re trying to quit using marijuana, will that improve outcomes?”

Trial participants will be randomly divided into two groups, one to receive treatment for tobacco concurrently with marijuana treatment for 12 weeks, and the other to be treated for marijuana first for 12 weeks, followed by another 12 weeks of tobacco treatment. Participants must come to an office in the University District twice weekly and have their urine tested for THC and other drugs.

Each marijuana-negative sample is rewarded with a Visa cash card, with the amount increasing for each consecutive marijuana-free sample. Participants who are successfully able to quit marijuana and provide negative samples can earn up to $435.

The trial uses a mix of motivational enhancement therapy and cognitive behavioral therapy. After an intake screening assessment with a researcher and a brief counseling session, the treatment is delivered primarily via computer. Participants complete weekly interactive sessions on a computer that are intended to increase motivation and teach skills to help meet their goals. The approach was developed by Alan Budney, a professor of psychiatry at Dartmouth College, who is conducting the trial in partnership with the UW.

Walker worked on a previous trial with Budney that tested the computerized treatment with an in-person version and found there was little difference in outcomes between the two approaches. Web-based treatments are less costly and more convenient, she said, and can provide access in settings where counselors may not be as available.

“It opens up a wide array of places where you can try to intervene with people — primary care settings, juvenile justice or other places where you can capture people in waiting rooms,” she said. “You can have them working on a computer, getting assessed and getting feedback, and if needed, getting referrals for additional treatment.”

The Innovative Programs Research Group, which focuses on providing early interventions for youth and adults struggling with behavioral issues, conducted a separate 2010 trial for people who wanted to quit marijuana and recruited more than 70 participants within weeks.

“Our phone was ringing off the hook,” said Lauren Matthews, project director for the current trial.

But that was before Washington and Colorado in 2012 became the first two states in the nation to legalize and regulate recreational marijuana use. Matthews said participants in the earlier trial seemed primarily motivated by the feeling that their pot use was out of control, rather than the drug’s illicit status.

As more states legalize marijuana, Walker said there is concern that cannabis is increasingly perceived as harmless. Some marijuana users are easily able to quit, she said, but others struggle and may experience withdrawal symptoms such as sleeplessness, irritability and loss of appetite. According to the National Institute on Drug Abuse, almost 4.2 million people in the U.S. abused or were dependent on marijuana in 2014, and studies suggest that 9 percent of users will become dependent at some point.

“There’s a segment of the population that has a really tough time quitting or cutting down, and even with treatment, quitting appears just as hard as with other substances including alcohol,” Walker said.

People interested in participating in the study, which is funded by the National Institute on Drug Abuse, can contact Matthews at uwmatts@uw.edu or 206-616-3235.