Are Heavy Smokers Different From Light Smokers?

To the Editor.—  I read with great interest the article by Killen et al¹ concerning differences between light and heavy smokers in terms of body weight, mood states, and symptom report. This article is an important contribution to the literature concerning psychological and sociodemographic characteristics of smokers. As the proportion of cigarette smokers in the United States declines, it would be reasonable to suspect that the majority of those who continue to smoke in the face of social disapproval and knowledge of their own health risk do so because they are physically or psychologically dependent on tobacco. Since both dependence and health risk increase with cigarette dose, study of pharmacologic and psychological factors related to maintenance of the smoking habit in heavy smokers is of particular importance.I do feel, however, that some caution should be exercised in the interpretation of the findings presented by Killen et al. Due