Evaluation of the relationship between depression and fibromyalgia syndrome: Why aren't all patients depressed?

Objective. To examine the relationship between fibromyalgia syndrome (FM) a nd depression by determining the set of factors that differentiate FM patie nts with and without depressive disorders. Methods. A sample of 69 patients with FM underwent a standardized tender po int examination and a semistructured psychological interview and completed a set of self-report inventories. Results. Of the sample, 39 met criteria for depressive disorder and 30 did not. Depressed patients with FM were significantly more likely to live alon e, report elevated functional limitations, and display maladaptive thoughts than nondepressed patients. Nondepressed patients were significantly more likely to have received prior physical therapy than depressed patients. Pai n severity, numbers of positive tender points, and pain intensity of tender points and control points did not differentiate the depressed and nondepre ssed patients. Discriminant analysis revealed that living status, the perce ption of functional limitations, maladaptive thoughts, and physical therapy treatment together identified diagnoses of depressive disorders for 78% of the patients. Conclusion. Concurrent depressive disorders are prevalent in FM and may be independent of the cardinal features of FM, namely, pain severity and hyper sensitivity to pressure pain, but are related to the cognitive appraisals o f the effects of symptoms on daily life and functional activities.