Duration of untreated illness and outcomes in unipolar depression: a systematic review and meta-analysis

Abstract

Background: To systematically review evidence of the effects of the duration of untreated depression on the clinical outcomes of patients suffering from Unipolar Major Depression.

Methods: A systematic review and meta-analysis of the evidence of duration of untreated depression and the effect it has on clinical outcomes in Unipolar Major Depression. Data used to this purpose were obtained from a literature search of the MEDLINE, Psychoinfo and Embase databases. Comparable data extracted from studies were entered and analysed using Cochrane Collaboration's Review Manager software Version 5.2.

Results: Ten studies were identified as meeting the inclusion criteria. Only three studies reported comparable data and were consequently used for the meta-analysis. Pooled data indicates the overall positive effect of shorter duration of untreated illness both in a patient's response to treatment (RR 1.70) and remission (RR 1.65). Other studies which were not included in the meta-analysis confirmed the importance of reducing delays in the treatment of depression in order to prevent the risk of worse outcomes and chronicity, in particular in patients presenting with a first episode of depression. Data regarding the association between the duration of untreated episode in recurrent depression and clinical outcomes are less evident.

Limitations: The heterogeneity of the selected studies was cause for limitations with regard to the carrying out of adequate meta-analysis.

Conclusions: There is evidence highlighting the importance of a reduced no-treatment interval for patients suffering Unipolar Depression. In particular, there is emphasis on the first episode of depression corresponding to the notion of reducing the duration of untreated illness.

Keywords: Meta-analysis; Outcomes; Remission; Response; Unipolar depression; Untreated depression.