Distinguishing Depression From Functional Impairment in the Medical Outcomes Study-Reply

In Reply.— Dr Jencks raises important issues regarding (1) the overlap of symptoms of depression with functional status, (2) comparison of patients with depressive symptoms above a specific threshold with medically ill patients without confirmed current symptoms, and (3) differences in case-finding methods. In response, we first discuss the nature of the conditions studied and then comment on each issue. Depression is a condition that is only defined when some symptoms are present; there is no truly asymptomatic depression. Thus, to study the morbidity associated with depression, one must identify persons who are actively depressed. Chronic medical conditions, however, are thought to be ongoing, nonreversible, pathological processes with varying symptom presentation. For such conditions, it makes sense to examine morbidity at any phase of the illness; a study based on only symptomatic cases of hypertension, for example, would not be particularly representative of patients with hypertension. As we noted in