Methodologie Differences in Major Depression and Panic Disorder Studies

To the Editor.—  In the October 1983, issue of the Archives, several articles were published that directly or indirectly addressed the relationship between anxiety disorders and major depression. At first glance, the reports appear to be contradictory. The studies by Crowe et al and Harris et al (Iowa studies)¹² found that major depression did not aggregate in the relatives of patients with panic as compared with control subjects. The study by Leckman et al (Yale study)³ found that major depression did aggregate in the relatives of patients with major depression and panic disorder compared with normal control subjects and depressed patients without an anxiety disorder.These discrepancies may be due to méthodologie, rather than real, differences. The méthodologie differences that stand out include the following.1. The selection of probands included primary depressives in the Yale study, V patients with chronologically primary anxiety disorders in the Iowa studies.