ADHD is one of the most frequently occurring disorders of children and adolescents and is a significant public health problem. The most common treatment for the condition is stimulant medication. However, there are an increasing number of children who are experiencing negative side effects from stimulants, such as dizziness, loss of appetite, and headaches; these side effects have made the need for alternative treatments all the more important. This study will compare the stimulant methylphenidate to the nonstimulant atomoxetine to determine which is more effective in treating ADHD symptoms in children and adolescents. The two medications differ in the neurotransmitters they influence. Stimulants such as methylphenidate act upon the neurotransmitter dopamine, while atomoxetine works on norepinephrine. It has been proposed that the difference in neurotransmitter stimulation may result in differences in an ADHD patient's response to treatment.~Participants will be randomly assigned to receive either methylphenidate or atomoxetine for between 4 to 6 weeks, depending on how soon they respond to the treatment. After the 4 to 6 week period, participants will be crossed-over to receive whichever medication they did not receive in the first part of the study.~Participants will have up to 14 weekly study visits. Over the first two visits, participants will undergo psychological and intelligence tests, a medical history, an electrocardiogram, blood and urine collection, and a physical exam. The remaining visits will occur weekly. During these visits, participants will receive their assigned medication and, along with their parents, will complete questionnaires about their response to treatment and any side effects they may be experiencing. The teachers of all participants will be asked to complete a questionnaire about their student's behavior at 4 different times during the study. Participant, parent, and teacher questionnaires will be used to assess the ADHD symptoms of participants, as well as self-report clinical scales completed by the participants.
This study will determine the effectiveness of stimulant and nonstimulant medication in treating the symptoms of attention deficit hyperactivity disorder (ADHD) in children and adolescents.