Refining models of dependence: variations across persons and situations.

Having established that tobacco smoking is addictive, research should proceed to refine our models of dependence on nicotine and other drugs. Current theories of addiction do not account for between- or within-subjects variations in addictive behavior. Recent evidence that some people can smoke for decades without developing dependence demonstrates the potential for individual differences in vulnerability to dependence. Study of such anomalous smokers may provide insight into the mechanisms underlying nicotine dependence. Current theory and data also fail to provide adequate accounts of situational variation in addictive behavior and of the developmental progression from initial experimentation to dependence.