Lilienfeld et al's critique of the use of the termcomorbidin psychopathological research is critically examined. They are incorrect in asserting that the original use of the term in medical epidemiology was intended to restrict it todiseaseentities. Furthermore, the ways in which medical comorbidity can be understood apply equally well to understanding the comorbidity of psychiatric or psychological disorders. Just as it has been useful to use the general termpsychiatric disordersto include symptom patterns and syndromes and few If any true diseases, so to it is useful to apply the generic term ofcomorbidityto the joint occurrence of psychiatric disorders. Because methodological factors can sometimes contribute to artifactual comorbidity which is uninformative about the disorders being studied is no reason to abandon the term comorbidity in psycho‐pathological researc