Study offers a new model for examining genetic risk associated with nicotine dependence
Some people casually smoke cigarettes for a while and then stop without a problem, while others develop long-term, several packs-per-day habits. A complex mix of environmental, behavioral, and genetic factors appear to raise this risk for nicotine dependence.
Studies of groups of twins suggest that 40 to 70 percent of the risk factors are heritable. Until recently, however, studies have only explained about 1 percent of the observed variation in liability to nicotine dependence, using a genetic score based on how many cigarettes a person smokes per day.
A new study led by psychologists at Emory University offers a new model for examining this genetic risk. It leveraged genome-wide association studies for a range of different traits and disorders correlated with nicotine dependence and explained 3.6 percent of the variation in nicotine dependence.