Does Early Improvement in Anxiety Symptoms in Patients with Major Depressive Disorder Affect Remission Rates? A Post-Hoc Analysis of Pooled Duloxetine Clinic Trials

Objectives: Patients with major depressive disorder (MDD) and a comorbid anxiety disorder or significant anxiety symptoms have decreased functioning, increased risk of suicidality, and worse post-treatment outcomes. This pooled analysis of 8 duloxetine MDD trials was designed to determine whether early improvement in anxiety symptoms predicts MDD remission. Methods: Eight trials were pooled. Patients with a baseline 17-item Hamilton Rating Scale for Depression (HA-MD17) anxiety/somatization factor score ≥7 were considered to have anxious depression. Early response on the HAMD17 total score was defined as a 20% reduction at weeks 2 or 4, a 30% reduction at weeks 2 or 4, or a 50% reduction at weeks 2 or 4 in the HAMD17 anxiety subscale. Each category was analyzed separately for all patients. MDD remission is a score of ≤7 on the HAMD17 total score at study endpoint. Results: The early responder group in each analysis showed greater numerical improvement at endpoint on the HAMD17 total score than the nonresponder group. Duloxetine showed statistically significantly greater improvement than placebo in most nonresponder and responder subgroups. There were no statistically significant interaction effects for the difference between duloxetine and placebo for any of the anxious categories. Conclusion: Although patients who responded in the various response categories had greater numerical improvement and greater remission rates than nonresponding patients, the response and nonresponse groups did not differ statistically regarding the treatment effect of duloxetine. Therefore, early improvement in anxiety symptoms was not a predictor of greater endpoint remission of depressive symptoms for duloxetine treatment.