Mental illnesses, such as major depression, bipolar disorder and post-traumatic stress disorder, affect nearly 1 in 5 adults in the United States, according to the National Alliance on Mental Illness. Many aspects of these illnesses remain something of a mystery, despite the progress made in understanding them by researchers studying these disorders in the last half century.
Even so, clinicians and researchers, together with patients and their families, have made significant strides identifying and treating mental illnesses. Two major diagnostic manuals — the Diagnostic and Statistical Manual of Mental Disorders (DSM), used primarily in the U.S., and the International Classification of Diseases (ICD), used internationally — provide clinicians, researchers and patients a structured approach to diagnosing mental health. Further, the federal National Institute of Mental Health also uses a new framework for researching mental illness, called the Research Domain Criteria, or R-DoC.