Fibromyalgia (FM) is a generalized, widespread chronic pain disorder and has an estimated prevalence of 2%-4% in the general population. Current pharmacological and psychological interventions frequently produce limited benefits in FM patients. Due to FM's strong association with psychological trauma causing neurobiological alterations in stress response, a trauma-focused psychotherapy is an innovative alternative treatment option. Eye Movement Desensitization and Reprocessing (EMDR) has been recognized by the World Health Organization as a first-line therapeutic tool for post-traumatic stress disorder and first evidence suggests that it is also beneficial for patients with FM. Given the complex etiology of FM, a combination of psychotherapy with other treatment options can maximize a potential therapeutic success. A possible candidate herby is transcranial Direct Current Stimulation (tDCS), a non-invasive stimulation technique, which can modify neural activities related to pain and which has shown short-term positive effects on chronic pain and quality of life in FM patients. The patient sample will consist of 96 female patients meeting 2016 American College of Rheumatology criteria for FM based on a clinical interview. They will be randomized to 20 sessions of EMDR plus tDCS or EMDR plus sham-tDCS, or Treatment as Usual (TAU). Therapists, raters, and patients will be kept blind to tDCS treatment conditions. Evaluations will be at baseline, post treatment at 6 months, and follow-up at 12 months. Hypotheses are that EMDR improves pain intensity and clinical symptoms at short and long-term, and that tDCS enhances this effect, which will be superior to tDCS-sham.