Guiding Dose Increases in Patients Incompletely Responsive to Usual Doses of Atomoxetine

Inclusion Criteria: * Outpatients who are at least 6 years of age and not more than 16 years of age at Visit 1 * Patients must meet DSM-IV diagnostic criteria for ADHD (any subtype) * Patients must have laboratory results showing no significant abnormalities (significant would include laboratory deviations requiring acute medical intervention or further medical evaluation) * Patients must be of normal intelligence as assessed by the investigator (that is, without a general impairment of intelligence and likely, in the investigator's judgment, to achieve a score of greater than or equal to 70 on an IQ test) * Patients must be able to swallow capsules Exclusion Criteria: * Patients who weigh less than 25 kg or greater than 70 kg at study entry * Patients with current or past Bipolar I or II disorder, psychosis, autism, Asperger's syndrome, or pervasive developmental disorder * Patients with a history of any seizure disorder (other than febrile seizures) or patients who have taken (or are currently taking) anticonvulsants for seizure control * Patients with a history of severe allergies to more than 1 class of medications or multiple adverse drug reactions * Patients with cardiovascular disease or other conditions that could be aggravated by an increased heart rate or increased blood pressure