One evening in the emergency room, I was asked to evaluate a patient requesting admission to the psychiatric unit. Gia was waiting for me, looking pale but fit. (All individuals identified only by their first name have been assigned pseudonyms, and their identifying details have been changed.) She had heard that the hospital was recruiting inpatients for a study of bipolar disorder and wanted to participate. She described herself as moody—upbeat for a few hours, then down, then happy again.