DEPRESSION AND ANXIETY 23:42–49 (2006) Research Article THE UTILITY OF SOMATIC SYMPTOMS AS INDICATORS OF DEPRESSION AND ANXIETY IN MILITARY VETERANS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE Christopher J. Ferguson, Ph.D., 1Ã Melinda Stanley, Ph.D., 2 Julianne Souchek, Ph.D., 3 and Mark E. Kunik, M.D., M.P.H. 2 The interrelationship between medical illnesses and psychological distress has received increasing attention in the last several years. Partly at issue is the best way to diagnose mental health problems such as depression and anxiety in medical populations. Specifically, are somatic symptoms a valid indicator of depression and anxiety in a medical population? Furthermore, do anxiety and depression remain as distinct constructs for this population, or do they combine to represent general distress? We examine these issues using confirmatory factor analysis in a sample of 202 military veterans with chronic obstructive pulmonary disease. Results indicate best fit for a model of depression and anxiety for which the constructs remained separate rather than as combined indicators of general distress. Furthermore, in this model, somatic symptoms are retained as valid indicators of psychological distress for this sample. Depression and Anxiety 23:42–49, 2006. & 2005 Wiley-Liss, Inc. Key words: depression; anxiety; medical patients INTRODUCTION The presence of depression and anxiety coexistent with medical conditions has received increasing atten- tion in recent years [Kessler et al., 2002; Kurina et al., 2001; Wetherell and Arean, 1997]. Difficulties arise in distinguishing between the symptoms of psychological and physical illnesses, particularly as relates to somatic symptoms that may be common to both [Clark et al., 2000]. Because somatic symptoms that play a promi- nent role among DSM-IV criteria for both depressive and anxiety disorders [American Psychiatric Associa- tion, 1994] may reflect medical disease, they may be less useful in distinguishing between mentally ill and non-mentally ill medical patients. However, the evi- dence for the inclusion or exclusion of somatic symptoms for diagnosing depression and anxiety in medical patients is contradictory [e.g., Clark et al., 1996; Epkins, 1996; Persons et al., 2003; Watson et al., 1995; Woody et al., 1998; Zung et al., 1990]. Furthermore, given the high clinical overlap of depressive and anxiety disorders among medical patients [Aydin and Ulusahin, 2001; Huang, 1997; Nisenson et al., 1998; Zung et al., 1990], it is unclear whether depressive and anxiety disorders can be Published online 28 November 2005 in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/da.20136 Received for publication 1 March 2005; Revised 22 September 2005; Accepted 28 September 2005 Contract grant sponsor: Department of Veterans Affairs, Veterans Health Administration, Health Services Research and Develop- ment Service; Contract grant number: IIR 00-097; Contract grant sponsor: Houston Center for Quality of Care and Utilization Studies, Health Services Research and Development Service, Office of Research and Development; Contract grant sponsor: South Central MIRECC, Department of Veterans Affairs. Ã Correspondence to: Christopher J. Ferguson, Ph.D., Depart- ment of Behavioral, Applied Sciences, and Criminal Justice. Texas A&M International University, Laredo, TX. E-mail: cjferguson1111@aol.com 1 Department of Behavioral, Applied Sciences, and Criminal Justice, Texas A&M International University, Laredo, Texas 2 Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston Center for Quality of Care and Utilization Studies, Michael E. DeBakey VAMC, Houston, Texas 3 Department of Medicine, Baylor College of Medicine, Houston Center for Quality of Care and Utilization Studies, Michael E. DeBakey VAMC, Houston, Texas r r 2005 Wiley-Liss, Inc.