The Way a Person Smokes Marijuana May Predict Future Dependence on the Drug

The way a person smokes marijuana is more important than how potent the drug is, or how much of the active ingredient THC it contains, in predicting whether the person will become dependent on the drug, a new study suggests.

While people who smoke potent marijuana do get more THC than those who smoke traditional varieties, their style of marijuana smoking is more important in predicting dependence, the researchers report in the journal Addiction.

Previous research on marijuana dependence has focused on how often a person uses the drug, lead researcher Peggy van der Pol of the Netherlands Institute of Mental Health and Addiction told Reuters. She studied 98 young adults who smoked marijuana at least three days a week for more than a year.

At the start of the study, one-third of participants met the criteria for marijuana dependence. All participants were interviewed a year-and-a-half after being recruited into the study, and then again a year-and-a-half after that. At both sessions, they were asked to smoke marijuana, while researchers observed. The researchers found people who smoked more potent marijuana inhaled less smoke, and smoked at a slower pace than their peers.

Smoking behaviors, such as how much of a marijuana joint they smoked, or how frequently they puffed, predicted dependence at the three-year mark, regardless of how much THC they were exposed to, or whether they were marijuana-dependent at the start of the study.