This document summarizes research on the impact of depression on healthcare expenses. It finds that costs associated with depression are substantial, including direct medical costs which were $12 billion in the 1990s and $98.9 billion in 2010, as well as workplace costs from lost productivity. Treatment options like pharmacotherapy and cognitive behavioral therapy can reduce costs, but their relative cost-effectiveness depends on factors like treatment duration and therapist salaries. While research is improving, gaps remain around issues like measuring quality-adjusted life years.