Smokers who have repeatedly tried to quit and failed over the years probably have genes that make it extra hard to overcome the addiction, the authors of a new study say. Thursday marks the 36th annual Great American Smokeout. To be sure, the dire health consequences of smoking are well-known, and many adults have quit over the past four decades. But some individuals have great difficulty quitting. The new study, by researchers at the University of Colorado, examined adult twins to look for a genetic influence in tobacco addiction.
