How much do we know about the functional effectiveness of interventions for depression? A systematic review

Abstract

Background: Functional difficulties are determined as one of the reasons for the public health priority given to depression. However, previous literature shows that the evidence on treatment effectiveness in depression does not reflect all relevant functional areas affected. This paper aimed to review recent literature and identify which areas are addressed and what are the gaps in the measurement of treatment effectiveness in depression.

Methods: Electronic search was performed in PsycINFO, PubMed, Web of science, and the Cochrane Central Register of Controlled Trials. A content item analysis of outcome measures was performed.

Results: Two hundred and fourty-seven studies were included. The functional areas addressed in the measurement process did not vary across studies assessing psychotherapeutic, pharmacological or alternative interventions. The content analysis revealed that 80% of the areas covered by instruments represented symptomatology. Many functional areas were insufficiently covered, whereas others like handling stress, solving problems, maintaining daily routine, problems in education, or participation in community, political or religious life were not addressed at all.

Limitations: Only articles in English were included and the time frame was limited.

Conclusions: More than 10 years after the first global burden of disease studies have been published evidence on the treatment effectiveness in depression is still based primarily on symptoms. Many important functional areas remain unexplored. Consequently the effectiveness of well recognized interventions might be overestimated. Future steps should include use of comprehensive tools, provision of detailed information on functional areas instead of global scores of instruments, and design of functional impairment oriented therapies.

Keywords: Depression; Functioning; Intervention; Outcome measure; Treatment effectiveness.