(i.e., no lines that overlapped or crossover). The only borderline exception to this case was in the adults, where the endorsement probability for withdrawal-related increased appetite for the moderate class overlapped that for the severe class. This moderate class in the adults was characterized by elevated endorsement probabilities for irritability, restlessness and increased appetite. There were no significant age differences across latent classes in the adults (p=.80), girls (p=.26) or boys (p=.17), suggesting that increases in nicotine withdrawal severity are not accounted for by age. The prevalence of each class is ample; in the adolescents, over 35% of the smokers fall into the severe class, and in the adults 51% fall into the moderate class and 18% into the severe class. This suggests that over a third of smokers are at increased risk of experiencing all of the DSM-IV nicotine withdrawal symptoms upon nicotine reduction.
