Comorbidity of Fibromyalgia and Psychiatric Disorders

Objective: To assess the co-occurrence offibromyalgia with psychiatric disorders in participants of afibromyalgia family study.

Method: Patients (probands) with fibromyalgia,control probands with rheumatoid arthritis, and first-degreerelatives of both groups completed a structured clinicalinterview and tender point examination. The co-occurrence oddsratio (OR) (the odds of a lifetime comorbid DSM-IV disorder in anindividual with fibromyalgia divided by the odds of a lifetimecomorbid disorder in an individual without fibromyalgia, adjustedfor age and sex) was calculated; observations were weighted bythe inverse probability of selection, based on the fibromyalgiastatus of the proband; and standard errors were adjusted for thecorrelation of observations within families. The study wasconducted from September 1999 to April 2002.

Results: We evaluated 78 fibromyalgia probandsand 146 of their relatives, and 40 rheumatoid arthritis probandsand 72 of their relatives. Among the relatives of both probandgroups, we identified 30 cases of fibromyalgia, bringing thetotal number of individuals with fibromyalgia to 108, comparedwith 228 without fibromyalgia. The co-occurrence ORs for specificdisorders in individuals with versus those without fibromyalgiawere as follows: bipolar disorder: 153 (95% CI = 26 to 902,p < .001); major depressive disorder: 2.7 (95% CI = 1.2 to 6.0,p = .013); any anxiety disorder: 6.7 (95% CI = 2.3 to 20, p < .001);any eating disorder: 2.4 (95% CI = 0.36 to 17, p = .36); and anysubstance use disorder: 3.3 (95% CI = 1.1 to 10, p = .040).

Conclusions: There is substantial lifetimepsychiatric comorbidity in individuals with fibromyalgia. Theseresults have important clinical and theoretical implications,including the possibility that fibromyalgia might shareunderlying pathophysiologic links with some psychiatricdisorders.