Peter P. Roy-Byrne, M.D. Karina W. Davidson, Ph.D. Ronald C. Kessler, Ph.D. Gordon J.G. Asmundson, Ph.D., R.D., Psych. Renee D. Goodwin, Ph.D., M.P.H. Laura Kubzansky, Ph.D. R. Bruce Lydiard, Ph.D., M.D. Mary Jane Massie, M.D. Wayne Katon, M.D. Sally K. Laden, M.S. Murray B. Stein, M.D., M.P.H., F.R.C.P.C. Anxiety Disorders and Comorbid Medical Illness Objective: To provide an overview of the role of anxiety disorders in medical illness. Method: The Anxiety Disorders Association of America held a multidisciplinary conference from which conference leaders and speakers reviewed pre- sentations and discussions, considered literature on prevalence, comorbidity, etiology and treatment, and made recom- mendations for research. Irritable bowel syndrome (IBS), asthma, cardiovascular disease (CVD), cancer and chronic pain were reviewed. Results: A substantial literature supports clinically important associations between psychiatric ill- ness and chronic medical conditions. Most research focuses on depression, finding that depression can adversely affect self-care and increase the risk of incident medical illness, complications and mortality. Anxiety disorders are less well studied, but robust epidemiological and clinical evidence shows that anxiety disorders play an equally important role. Biological theories of the interactions between anxiety and IBS, CVD and chronic pain are presented. Available data suggest that anxiety disorders in medically ill patients should not be ignored and could be considered conjointly with depression when developing strategies for screening and intervention, particularly in primary care. Conclusions: Emerging data offer a strong argument for the role of anxiety in medical illness and suggest that anxiety disorders rival depression in terms of risk, comorbidity and outcome. Research programs designed to advance our understanding of the impact of anxiety disorders on medical illness are needed to develop evidence-based approaches to improving pa- tient care. (Reprinted with permission from General Hospital Psychiatry 2008; 30:208 –225) INTRODUCTION Mental disorders occur with chronic medical conditions in many patients, causing significant role impairment, work loss and work cut-back (1, 2). Depression increases symptom burden and functional impairment and worsens prognosis for heart disease, stroke, diabetes mellitus, HIV/AIDS, cancer and other chronic illnesses (3–5). One na- tionally representative survey of over 130,000 Ca- nadian adults demonstrated that depression inde- pendently increased role impairment by 21% compared to healthy controls. However, when de- pression occurred along with chronic lung disease, diabetes mellitus or heart disease, the rate of disabil- ity increased by over 50% (5). A more complete understanding of the adverse effect of depression on biological and self-care (e.g., adherence to diet, smoking cessation, exercise, medications) mecha- nisms and findings from treatment studies is emerging to guide patient care (6 –14). These data paint a compelling picture of the importance of depression in medical illness. Much less is known about the impact of anxiety disorders on function and outcome in persons with chronic medical illness. There is convincing evi- dence that anxiety is associated with high rates of medically unexplained symptoms and increased utilization of healthcare resources (4, 15–19). Moreover, anxiety disorders are strongly and inde- pendently associated with chronic medical illness (20, 21), low levels of physical health-related qual- ity of life, and physical disability (21–24). Indeed, the disability and related poor physical and eco- nomic outcomes associated with anxiety disorders may be as great as with depression. In a sample of 480 primary care patients, the probability of miss- ing time from work in the prior month for persons with an anxiety disorder (OR: 2.22) was as great as for persons with major depression (OR: 2.15) (25). In patients with diabetes, comorbid panic disorder had a significant adverse effect on symptom bur- focus.psychiatryonline.org FOCUS Fall 2008, Vol. VI, No. 4 467 INFLUENTIAL PUBLICATIONS