Arthritis and psychiatric disorders: disentangling the relationship.

Various studies have demonstrated a link between having arthritis increased the risk for developing psychiatric arthritis, particularly rheumatoid arthritis (RA) and osteoarthritis (OA), and psychiatric disorders. More than two decades ago, Wells et al. [1] published data from the NIMH catchment area study in the United States showing that persons with arthritis had a lifetime prevalence rate of psychiatric disorders of 63.6% and a 6-month prevalence rate of 42.5%. These rates were alarming inasmuch as they exceeded those found in persons with potentially lifethreatening illnesses such as COPD, diabetes, hypertension, and cardiovascular disease. While the authors found that having any chronic illness increased the risk of psychiatric disorder, these cross-sectional, epidemiological data did not address the important questions of whether arthritis preceded or followed the development of psychiatric disorders, or why these associations were found in the first place. Subsequently, corroborating evidence has been found in studies reporting rates of mood disturbance ranging from 15% to as high as 45% in persons with such conditions as RA, systemic lupus erythematosus, and fibromyalgia [2–4]. Evidence is also accumulating that anxiety disorders are prevalent in persons with arthritis [5]. Understanding the factors associated with the heightened psychiatric comorbidity in such studies represents an important challenge for behavioral medicine researchers and arthritis health professionals who serve these populations. Accordingly, the major purpose of the Land et al. [6] study was to clarify the direction of the relationship between arthritis and psychiatric disorders by examining whether