Risk Rates for Depression-Reply

Abstract

In Reply.— The great differences in reported familial morbid risk for affective disorders, especially for major depression, are remarkable. We¹have tabulated morbid risk estimates for major depression in different studies: in 13 studies of relatives of bipolar patients, the range was 0.5% to 22.4%; in seven studies of unipolar patients the range was 5.1% to 17.5%; and in three studies of normal control subjects, the range was 0.7% to 5.8%. These numbers cause one to ask if reliable estimates are at all possible, and what the true morbid risks are. I submit that there is no "true" morbid risk, and that observed rates may vary for many demonstrable reasons (Table). These include cultural factors (nationality, urban or rural residence, and age at time of examination) and procedural factors (diagnostic criteria and the method of obtaining information). But reliable, reproducible estimates can be achieved with careful attention to procedure and diagnostic