The purpose of this research was to provide basic data in the control of depression found in patients with fibromyalgia by analysing the main factors that affect them.

The subjects were 207 out-patients in three university medical centers diagnosed with fibromyalgia according to the conditions by American College of Rheumatology (1990). Depression was measured by the CES-D Scale. Dependant variables, such as stress and anxiety were measured by the VAS Scale and physical activity was measured using 10(4-point-scale) questions developed by the researcher. The number of tender points was converted to scores based on the criteria of the ACR(1990) and of Yunus. Self-efficacy was measured by the Self-Efficacy Scale developed by Lorig et al.(1989) for arthritis patients.

The main factors that affect depression of patients with fibromyalgia were self-efficacy, anxiety, physical activity, tender points fatigue, and family support, which explained 49% of the depression.

It has been confirmed that the regression equation model of this research may serve as a predictor of depression in patients with fibromyalgia.