Why marijuana users end up feeling worse

Adolescents and young adults who smoke marijuana frequently may attempt to manage negative moods by using the drug but end up feeling worse, says a new study.

"Marijuana use is a vicious circle. People feel bad, they smoke marijuana and they might momentarily feel better, but then they feel worse. They do not necessarily link feeling bad after using with the use itself," explained lead study author Lydia A. Shrier from the division of adolescent and young adult medicine at the Boston Children's Hospital.

Young people who use marijuana frequently experience an increase in negative affect in the 24 hours leading up to a use event.

According to Shrier, using marijuana as a coping technique may make it harder for people to stop using the drug.

"Marijuana use can be associated with anxiety and other negative states," she stressed.

For the study, Shrier and colleagues recruited 40 people in age group 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 hand-held computer that signalled them at random times 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.

Researchers found that negativity was significantly increased during the 24 hours before marijuana use compared with other periods.

However, positive feelings 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 negativity," Shrier maintained.

The study collected data in real time to assess mood and marijuana use events.

"We were able to identify the mood that was occurring in the 24 hours before marijuana use and compared it with moods at other times," Shrier concluded.

The paper appeared in the Journal of Studies on Alcohol and Drugs.