Mental illness affects one in four adults in the United States; approximately 61.5 million Americans experience mental illness in a given year. According to the National Alliance for the Mentally Ill, the impact of serious mental illness costs Americans $193.2 billion in lost earnings per year. In addition, mental illness patients have an increased risk of having chronic medical conditions, leading to increased costs and emergency service utilization for those conditions. In addition to substantial costs, patients with psychiatric illness are difficult to treat. More than two-thirds of patients with depression do not respond to first line therapy. Treatment often involves numerous trials of individual agents and combinations of medications in order to achieve optimal response. Pharmacogenetic testing is being used in more settings to guide treatment decisions.
