Assessing remission in major depressive disorder and generalized anxiety disorder clinical trials with the discan metric of the Sheehan disability scale

Abstract

Relatively little research has focused on the relationship between functional remission and symptomatic remission in mood and anxiety disorders. This study investigates the relationship and synchrony between symptomatic and functional remission in outpatients with major depressive disorder (MDD) and generalized anxiety disorder (GAD). Using data from three MDD (N=1419) and four GAD (N=1847) randomized, placebo-controlled duloxetine studies, we calculated the percentages of patients meeting symptomatic, functional, and combined functional-symptomatic remission criteria for each disorder. We also calculated mean depression [17-item Hamilton depression rating scale (HAMD₁₇), Montgomery-Asberg depression rating scale] scores and mean anxiety (Hamilton anxiety rating scale) scores for patients meeting Sheehan disability scale (SDS) functional remission and the mean SDS scores for patients with symptomatic remission. Among the patients with MDD, 38% achieved symptomatic remission (HAMD₁₇ ≤ 7), 32% achieved functional remission (SDS ≤ 6), and 23% achieved combined functional-symptomatic remission. Mean HAMD₁₇ and Montgomery-Asberg depression rating scale scores for patients with functional remission were approximately 6. Mean SDS total scores for patients with symptomatic remission were 7.1 (patients with HAMD₁₇ ≤ 7) and 8.6 (patients with Montgomery-Asberg depression rating scale ≤ 10). Among the patients with GAD, 30% achieved symptomatic remission (Hamilton anxiety rating scale ≤ 7), 45% achieved functional remission (SDS ≤ 6), and 25% achieved combined symptomatic-functional remission. The mean Hamilton anxiety rating scale score in GAD was approximately 8 for patients with functional remission and the mean SDS total score was approximately 4 in patients with symptomatic remission. The study shows that functional remission does not always move in tandem with symptom remission and provides useful anchor points or rules of thumb for evaluating symptomatic and functional remission in MDD and GAD.