Marijuana users who feel low get high

"Young people who use marijuana frequently experience an increase in negative affect in the 24 hours leading up to a use event, which lends strong support to an affect-regulation model in this population," says the study's lead author Lydia A. Shrier, M.D., M.P.H., of the division of adolescent and young adult medicine at Boston Children's Hospital.

She notes that using marijuana as a coping technique for negative affect may make it harder for people to stop using the drug.

"One of the challenges is that people often may use marijuana to feel better but may feel worse afterward," she says. "Marijuana use can be associated with anxiety and other negative states. People feel bad, they use, and they might momentarily feel better, but then they feel worse. They don't necessarily link feeling bad after using with the use itself, so it can become a vicious circle."

For the study, Shrier and colleagues recruited 40 people, ages 15 to 24, who used marijuana at least twice a week, although their average was 9.7 times per week. They were trained to use a handheld computer that signaled them at a random time within three-hour intervals (four to six times per day) for two weeks. At each signal, participants were asked about their mood, companionship, perceived availability of marijuana, and recent marijuana use. Participants were also asked to report just before and just after any marijuana use. They completed more than 3,600 reports.

The researchers found that negative affect was significantly increased during the 24 hours before marijuana use compared with other periods. However, positive affect did not vary in the period before marijuana use compared with other times.

Also, neither the availability of marijuana nor the presence of friends modified the likelihood that chronic users would use marijuana following a period of negative affect.

The study is unique in that it collected data in real time to assess mood and marijuana use events. The study thus was able to identify mood that was occurring in the 24 hours before marijuana use and compared it with mood at other times, Shrier reports.

"There are a host of limitations with retrospective assessments, such as asking people 'the last time you used marijuana, why did you use it?'" according to Shrier. "We weren't asking people to predict anything or to recall anything -- we were just asking them to give us reports about how they were feeling right now. We were able to put under a microscope the association between those feelings and subsequent marijuana use."

Shrier says it could be beneficial for clinicians and counselors to help their patients identify patterns of negative affect and to implement alternative mood-regulation strategies to replace marijuana use.