Stimulant Versus Nonstimulant Medication for Attention Deficit Hyperactivity Disorder in Children

Measuring and Predicting Response to Atomoxetine and Methylphenidate

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.

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.

Inclusion Criteria:

• Meets DSM-IV-TR criteria for ADHD
• Scores at least 1.5 standard deviation higher than age and gender mean on ADHD-RS keyed to ADHD subtype
• CGI Severity ADHD Rating greater than or equal to 4
• Currently attends school with at least 3 months left in high school
• Currently lives at home with parent(s) or legal guardian(s), now and for the past year before study entry, and is expected to remain there
• Normal physical exam, laboratory tests, and electrocardiogram
• Pulse and blood pressure within 95% of age and gender mean
• Full Scale IQ is greater than or equal to 75 OR if the results of testing indicate that Full Scale IQ is not a good indicator of intellectual ability, a General Ability Index greater than or equal to 75
• Weight is between 20 and 85 kilograms
• Able to swallow pills
• Parent or guardian willing to provide informed consent

Exclusion Criteria:

• History of atomoxetine or methylphenidate intolerance
• Any existing medical condition for which study medications are contraindicated
• If the child is in psychotherapy, no changes in therapy expected during the study trial
• Presence of any of the following: autism, mental retardation, schizophrenia, a psychotic disorder, bipolar disorder, severe depression, or conduct disorder
• Presence of a comorbid disorder that should be the primary focus of treatment
• Presence of a medical or neurological disorder precluding study medications or assessing ADHD
• Allergic reactions to multiple medications
• History of alcohol or drug abuse in the 3 months before study entry, or positive urine toxic screen that is not explained by a time limited medical circumstance
• Involved in a medication treatment study in the 30 days before study entry
• Female who is sexually active and is unwilling to use birth control
• Evidence of child abuse or neglect