A critical review of published economic modelling studies in depression.

Depression is a very costly chronic disease. An important cost driver is treatment failure caused by patient noncompliance due, in part, to the adverse effects of medications. Additionally, inadequate duration of therapy and inappropriate medication switching contribute to the high cost of treatment. With the epidemiological data for depression demonstrating a rise in both incidence and prevalence over the last 20 years, and the fact that many of the newer antidepressants will see patent expiry in the near future, previous antidepressant cost-effectiveness scenarios are likely to change. As economic models play an increasingly important role in therapeutic decision-making, clinicians are encouraged to understand the strategies and methods involved in modelling antidepressant therapy. The aim of this review of the literature and synthesis of the various techniques important to the modelling of antidepressant therapies is for the practitioner to gain an increased understanding of the modelling methods previously utilised and be in a position to better evaluate future health economic models for the treatment of depression.