Second, the lifetime time frame entails the risk that comorbid conditions may not have occurred during the same time period. The onset internalizing and externalizing disorders may have occurred after the onset – or even after remission – of alcohol dependence. Thus, their associations with alcohol dependence reflect an increased likelihood of having ever been dependent rather than an increased risk of becoming dependent as a function of antecedent or concurrent psychopathology. This limits the usefulness of the study results for delimiting the role of comorbid psychopathology in the etiology of alcohol dependence and, perhaps even more importantly, for making clinical recommendations related to screening and treatment.
