Depression is one of the most common conditions seen by primary care physicians second only to hypertension. The 12-month prevalence was 6.9% among U.S. adults in 2012. Lifetime prevalance was estimated at 16% in 2008 by the CDC; large scale studies have suggested that the ilfetime risk of men (97 – 12%) is significantly less than women (20 – 25%). Depression can begin in early adulthood, with a peak onset between ages 20 – 30. Over half the people who experience an episode of major depression are at risk for a relapse and recurrence (Cutler, J. Charon, R. 1999).

Depression costs the United States economy more than $210 billion annually every year  (Greenberg, 2015). 350 million people in the world suffer from depression; it is the leading cause of disability around the world.

Depression has a high rate of morbidity and mortality when left untreated. Most patients do not necessarily complain of feeling depressed, but rather that they have a lack of interest or pleasure in activities, may have somatic complaints, or vague unexplained complaints. In one study, 69% of diagnosed depressed patients reported unexplained physical symptoms as their chief complaint (NYCDOH, 2006). Unlike patients with depression in psychiatric inpatient or outpatient care settings, persons suffering from depression in primary care settings often present as “undifferentiated” patients.

Depression is often undiagnosed and untreated, and even when it is diagnosed it is often under treated. Primary care physicians must remain alert to effectively screen for depression in their patients. Barriers to effective screening include inadequate education and training, limited coordination with mental health resources, time constraints, poor systematic follow up, and inadequate reimbursement. It is sometimes difficult for primary care providers to determine if a patient is depressed as opposed to experiencing a normal response to the challenges of everyday life. Gender, age, culture, and language of the patient and the physician may create further barriers. Furthermore, persons with mood disorders also may have enormous stigma associated with being mentally ill – and may see it as a sign of weakness, fear the criticism of other people, or be concerned that they will be institutionalized.
Because depression ia strongly linked to excess morbidity and mortality, it cannot be left undiagnosed or untreated by primary care doctors. Patients who suffer from diabetes, ischemic heart disease, stroke, or lung disorders that have concurrent depression have poorer outcomes than those without depression. Fifteen percent of patients with severe mood disorders die from suicide. In one study among older patients who committed suicide, 20% visited their primary care doctor on the same day as their suicide (NYCDOH, 2006).