Are Heavy Smokers Different From Light Smokers?-Reply

In Reply.—  Dr Istvan says that we should not have concluded that heavy smokers suffered from a more severe tobacco withdrawal syndrome than light smokers and supports his assertion by citing studies that he says show precessation differences between heavy and light smokers on measures of anxiety and other mood states. However, the evidence from these reports would appear to be, at best, inconclusive. For example, in the study by Williams,¹ measures were obtained (a) after at least ten hours of self-reported abstinence and (b) after the smoking of a cigarette. Heavy smokers differed from light smokers on six of 15 mood scales administered during a period of abstinence. However, Williams found no main effects for smoker type (heavy-medium vs light) after subjects had resumed smoking. In the study by McCrae and colleagues,² heavy smokers appeared more anxious than nonsmokers. Analyses comparing heavy and light smokers, if conducted,