An overview of the effectiveness of psychological therapy for depression and stepped care service delivery models

Depression is one of the most prevalent health disorders globally and causes significant distress and cost to the sufferer and society. Psychological therapy for depression has been recommended over a number of decades; however, access to these treatments remains limited. Cognitive behaviour therapy, behavioural activation, self-help approaches, interpersonal therapy and non-directive therapy all demonstrate moderate to large effect sizes when compared to treatment as usual. Differences between psychological interventions however are small and unstable when reviewed in meta-analyses suggesting that for most people adding complexity to treatment does not result in improved outcomes. Stepped care is one system used to organise delivery of psychological therapy that stratifies interventions across several levels of symptom severity. There is debate regarding the ideal design and operation of this complex system resulting in considerable variability in its use in clinical settings. Further research is needed to identify the most cost effective approach to the delivery of psychological therapies for depression as we need to continue to reduce the gap between demand and access to therapy.