The purpose of this trial is to test the value of dose increases in patients with residual ADHD symptoms after treatment with the usual target dose 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