Comorbidity.

People with primary psychiatric disorders have high rates of substance abuse and addictive disorders and vice versa. These clinical conditions are defined in the Diagnostic and Statistical Manual of Mental Disorders: DSM 5 (2013) of the American Psychiatric Association, which is the widely used nomenclature for mental disorders. In the fields of clinical psychology and psychiatry, the terms comorbidity or dual diagnosis, generally apply to the presence of one or more serious mental disorders (SMDs) and one or more substance use disorders (SUDs). However, comorbidity can also refer to the co-occurrence of two or more serious mental disorders such as personality disorders .