Duration of untreated illness as a predictor of treatment response and clinical course in generalized anxiety disorder

Introduction: The aim of the present study was to investigate the impact of the duration of untreated illness (DUI) - defined as the time elapsing between the onset of generalized anxiety disorder (GAD) and the first adequate pharmacologic treatment - on treatment response and clinical course in a sample of subjects with GAD. Methods: One hundred patients with GAD, diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-Text Revision criteria, were enrolled and their main demographic and clinical features collected. Patients were then treated with selective serotonin reuptake inhibitors or venlafaxine for 8 weeks in open-label conditions. Treatment response and other clinical variables were analyzed after dividing the sample into two groups according to DUI (DUI ≤12 months and DUI >12 months). Results: When the DUI was computed with respect to the first antidepressant treatment (DUI-AD), a higher improvement (Clinical Global Impressions-Severity of Illness scale) after the pharmacologic treatment was found in the group with a shorter DUI (analysis of variance with repeated measures: time effect F=654.975, P