The state of implementation science in major depressive disorder: A narrative review

Major depressive disorder (MDD) is one of the most prevalent and disabling mental disorders with high recurrence rate. There is often a gap between scientific evidence related to the effective and cost-effective treatment of depression and clinical practice. Implementation science is a field of inquiry that aims to advance the process of applying evidence-based interventions to real-world problems. Implementation research consists of two broad phases. The first phase seeks to identify the gaps that exist between evidence and practice and their impact on outcomes. The second phase, building on the first, evaluates the effectiveness of implementation strategies by examining various implementation indicators to support the adoption and scale up of interventions. Although implementation research can facilitate the uptake and adoption of evidence-based interventions, it is underused in depression research. In this narrative review, the authors will introduce the definition of implementation science and the state of implementation science in MDD in order to support more widespread use of implementation science for scaling up evidence-based interventions.