Central pain networks in the brain are dysregulated in persons with fibromyalgia (FM). Thus, the investigators propose that cranial electrical stimulation (CES) that works on the brain may ameliorate symptoms of FM by interacting with the central pain networks. The specific aims of this randomized, controlled, three-group pilot study design are to: (1) determine differences in pain over time between the active CES, sham device, and usual care (UC) groups; (2) explore differences in brain activity in pain processing regions (i.e., cingulate, insula, prefrontal and somatosensory cortices, amygdala, and thalamus) between the active CES, sham device, and UC groups in a subset of 12 participants (6 in each device group); (3) determine the effects of CES on other symptoms (fatigue, sleep disturbances, depression, perceived stress) and functional status, and blood pressure over time between the active CES, sham device, and UC groups; and (4) determine the amount of influence that selected psychological factors (negative affect, catastrophizing, and other personality characteristics) have on group differences in pain, other symptoms, functional status, and brain activity.