The depression treatment cascade in primary care: a public health perspective.

Major depressive disorder (MDD) is common and costly. Primary care remains a major access point for depression treatment, yet the successful clinical resolution of depression in primary care is uncommon. The clinical response to depression suffers from a "treatment cascade": the affected individual must access health care, be recognized clinically, initiate treatment, receive adequate treatment, and respond to treatment. Major gaps currently exist in primary care at each step along this treatment continuum. We estimate that 12.5% of primary care patients have had MDD in the past year; of those with MDD, 47% are recognized clinically, 24% receive any treatment, 9% receive adequate treatment, and 6% achieve remission. Simulations suggest that only by targeting multiple steps along the depression treatment continuum (e.g. routine screening combined with collaborative care models to support initiation and maintenance of evidence-based depression treatment) can overall remission rates for primary care patients be substantially improved.