This study will use the combined N-of-1 method to compare the effectiveness of the combination therapy amitriptyline and fluoxetine (AM+FL) versus amitriptyline (AM) alone in patients with fibromyalgia (FM). It will also compare community-based and center-based trial results. We will ask community-based, board-certified rheumatologists to participate as investigators and we will also carry out a center-based study (at Newton-Wellesley Hospital). Physicians will ask patients meeting eligibility criteria to participate in this study and undergo an N-of-1 trial.