The study is open-label. All of the subjects in this study will receive the active medicine fluoxetine orally dissolving tablets (ODT). Children will begin by receiving a daily dose of 2mg fluoxetine for two weeks. The family and child will be asked to come back to the clinic 2 weeks later and, depending on the child's tolerance and response to the medicine, may have his or her dose increased to 4mg/day. After this visit, the time between visits to the clinic and the dose that the child will receive will be decided by the study investigator based on their clinical judgment on benefit versus tolerability. The largest daily dose of fluoxetine that the child could receive in this study is 54mg.