Conceptual overview of the online study environment and matching algorithm. (a) The number of patients choosing to experiment with lithium carbonate peaked in the months after publication of a small clinical trial in Italy. Preliminary negative results from this patient-led study were announced before the first randomized control trial had started recruitment. (b) Aggregate view of FRS scores for all 348 patients analyzed in this study. These data were publicly available online during the study. (c) Illustration of disease progression curves of control individuals who are good and poor matches for a particular patient. Both control individuals would be considered comparable by traditional matching criteria. The PatientsLikeMe matching algorithm minimizes the area between the disease progression curves for a target patient and a control. Adapted from [] with permissions.