Somatization in primary care: it's time for parity.

Symptoms account for over half of all outpatient encounters, or an estimated 400 million clinic visits in the United States each year [1]. However, clinical research typically has focused on defined diseases that, therefore, constitute the core curriculum of medical education. Fatigue related to heart failure or depression, or abdominal pain resulting from an ulcer, are much less frustrating than instances where these symptoms are either idiopathic or part of poorly understood illnesses such as chronic fatigue syndrome or irritable bowel syndrome. Previous studies have shown that: at least one-third of physical symptoms are medically unexplained [2–4]; women report higher rates of most symptoms, both overall as well as unexplained [5]; and visits related to unexplained symptoms are rated by primary care physicians as among their most difficult encounters [6–8]. Similarly, Hartz and colleagues report, in this issue of the Journal, that unexplained symptoms were prevalent among Medicaid patients in Iowa, more common in women, and particularly dissatisfying for physicians to manage [9]. Depressive, anxiety, and somatoform disorders encompass the bulk of a primary care clinician’s caseload in terms of mental health problems. Depression has garnered the most attention, both from a clinical and research standpoint, whereas advocacy for better management of anxiety disorders has been emerging. Somatoform disorders remain the ugly duckling. However, undue partitioning of these three categories of disorders ignores their commonalities. The similarities are substantial. First, these disorders are characterized by considerable overlap of symptoms, both psychological and somatic [3,4,10– 12]. Overlap can exist at several levels: patients often have several “threshold” disorders (e.g., major depression and panic disorder; dysthymia and somatization disorder)—this is referred to as psychiatric comorbidity; symptom criteria may be shared by multiple disorders (e.g., fatigue, insomnia, and trouble concentrating are diagnostic criteria for both depressive and anxiety disorders); and symptoms that are criteria for one disorder are prevalent, albeit not explicit criteria, in another disorder (e.g., somatic symptoms that may constitute a somatoform diagnosis are also exceptionally common in patients with depressive and anxiety disorders). Although this is not a plea for resurrecting a unitary disorder of distress (such as “neurosis”), the substantial symptom overlap in primary care patients also cautions us against obsessive–compulsive nosological splitting. Somatoform disorders are subject to a diagnostic bias not applied to depressive and anxiety disorders for which comorbid diagnoses are permitted if not encouraged. Indeed, DSM-IV allows concurrent diagnoses not only across depressive and anxiety categories but even within a single category, such as “double depression”—major depression and dysthymia. In contrast, a number of somatoform diagnoses are precluded if, in the opinion of the clinician, the somatic symptoms are “better accounted for by a mood or anxiety disorder.” This hierarchical rule raises concerns about the accuracy and reliability of attributing somatic symptoms to depression or anxiety. More importantly, this rule ignores the fact that somatization has an independent and additive effect beyond depression and anxiety on a number of domains, including functional impairment, physician-experienced difficulty, and health care utilization and costs [13]. Like double depression, the depressed or anxious paRegenstrief Institute for Health Care and the Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana. Address reprint requests to: Kurt Kroenke, MD, Regenstrief Institute for Health Care, RG-6, 1050 Wishard Blvd., Indianapolis, IN 46202.