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Research Brief

Anxiety disorders are among the most prevalent mental health disorders in the United States. About 18 percent of the U.S. population suffers from an anxiety disorder each year, and almost 29 percent will experience an anxiety disorder at some point in their lives. Studies show that patients with anxiety disorders have difficulty in functioning (e.g., lack of interest in or avoidance of work, social, and home activities) and decreased well-being (e.g., pain, discomfort, depression).

While the negative effects of anxiety are fairly well established, few studies have compared differences in functioning and disability associated with different anxiety disorders. In addition, little is known about how having more than one anxiety disorder affects functioning and disability.

This study compared the effect of combinations of anxiety disorders in primary care outpatients. A total of 1,004 patients with panic disorder, generalized anxiety disorder, social anxiety disorder, or posttraumatic stress disorder (PTSD) provided information about their mental and physical functioning and disability.

Key Findings

There were few relative differences in functioning among patients with only one anxiety disorder. For this group (42 percent of the sample), all measures of functioning and disability, except for physical functioning, showed substantial impairment compared with general population norms. Those patients with social anxiety were most restricted in their work, social, and home activities and spent more days limited in activities, as did those with PTSD. Those with generalized anxiety were the least impaired.

The burden of disability was greater as the number of anxiety disorders increased. More than half of patients in the sample (57 percent) had more than one anxiety disorder—38 percent had two disorders, 16 percent three, and 3 percent all four.

  • As the number of disorders increased, functioning levels (including ability to perform usual activities or to participate in work, social, and family activities) tended to deteriorate.
  • Patients with multiple anxiety disorders had a much higher rate of depression than did those with only one anxiety disorder: 88 percent compared with 56 percent, respectively.
  • The combination of social anxiety and panic disorder appeared to be particularly debilitating. Patients with both conditions had the lowest rating of their overall health-related quality of life.

The findings indicate that a focus on the unique effects of specific anxiety disorders is inadequate, as it fails to address the more pervasive impairment associated with multiple anxiety disorders. Further, the findings reinforce the seriousness of social anxiety disorder and suggest a potential need for further screening and outreach to identify these patients and facilitate their access to treatment.

This report is part of the RAND research brief series. RAND research briefs present policy-oriented summaries of individual published, peer-reviewed documents or of a body of published work.

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