The relationship between anxiety disorders and physical disorders in the U.S. National Comorbidity Survey

Although depression has clearly been shown to be associated with physical disorders, few studies have examined whether anxiety disorders are independently associated with medical conditions after adjusting for comorbid mental disorders. We examined the relationship between anxiety disorders and a wide range of physical disorders in a nationally representative sample. Data came from the National Comorbidity Survey (N=5,877, range=age 15-54 years, response rate=82.4%). The Composite International Diagnostic Interview [Kessler et al., 1998] was used to make DSM-III-R [American Psychiatric Association, 1987] mental disorder diagnoses. Physical disorders were assessed based on a list of several conditions shown to respondents. All analyses utilized multiple logistic regression to examine the relationship between past-year anxiety disorder diagnosis and past-year chronic physical disorder. Anxiety disorders were positively associated with physical disorders even after adjusting for mood disorders, substance-use disorders, and sociodemographics. Among respondents with one or more physical disorders, a comorbid anxiety disorder diagnosis was associated with an increased likelihood of disability even after adjusting for severity of pain, comorbid mood, and substance use disorders. Among specific anxiety disorders, posttraumatic stress disorder, panic attacks, and agoraphobia were more likely to be associated with specific physical disorders than generalized anxiety disorder, social phobia, or simple phobia. There is a strong and unique association between anxiety disorders and physical disorders. Clinically, the presence of an anxiety disorder among patients with physical disorders may confer a greater level of disability.