Does self-efficacy mediate the relationship between disease impact and depression symptoms among people with fibromyalgia? A longitudinal multilevel mediation model

The purpose of the present study was to determine whether self-efficacy mediated the relationship between perceived disease-specific impact and symptoms of depression in a sample of 600 individuals (M-age = 53.92 years, SD = 11.45 years) with fibromyalgia over 18 months. A 1-1-1 longitudinal multilevel mediation analysis was conducted using participants' total scores on the Fibromyalgia Impact Questionnaire (FIQ), the Arthritis Self-Efficacy Scale (ASES), and the Center for Epidemiological Studies Depression Scale (CES-D) at four measurement times (baseline, six months, one year, and 18 months later). The results indicated that self-efficacy was a significant partial mediator of the direct negative influence fibromyalgia impact had on depression symptoms at both the within- and between-individual levels over the course of the study. The findings provide further evidence that enhancing self-efficacy beliefs may help buffer the negative psychological consequences of fibromyalgia and suggest that other mechanisms may affect the relationships in the model.