Duration of untreated illness and antidepressant fluvoxamine response in major depressive disorder.

Aims: The aim of this study was to analyze the relation between treatment response and the duration of untreated illness (DUI) in 133 outpatients with the first major depressive disorder (MDD) episode.

Methods: A logistic regression was performed with DUI, sex, age at onset, and score for 17 items on the Hamilton Depression Rating Scale at the time of start of fluvoxamine treatment as the explanatory variables, and the response and the remission as the outcome variables.

Results: Regression analysis showed significant association between the response and DUI (P < 0.0001), and between the remission and DUI (P < 0.0001), respectively. The remission rate gradually decreased with longer DUI.

Conclusion: Early treatment of first depressive episodes is important because a shorter DUI implied better remission outcomes.