To look at the cognitive effects of abilify in children with a primary diagnosis of Attention Deficit Hyperactivity Disorder. To examine the safety, effectiveness and tolerability of abilify in children with a primary diagnosis of Attention Deficit Hyperactivity Disorder.

This will be a prospective, open-label, 6-week trial of APZ in outpatient children 8-12 years of age with a primary diagnosis of ADHD free of other major psychopathology. The six-week treatment phase will be proceeded by a 1-3 week screening phase.

The study cohort will consist of 10 children with ADHD combined type and 10 children with ADHD predominantly inattentive type who complete the study.

Cognitive measures will be assessed prior to APZ therapy and after 6 weeks of APZ treatment.

Safety assessments and measures of ADHD symptomatology will be collected prior to and during APZ therapy.

While receiving APZ treatment, patients will be seen at baseline, Week 1,2,3,4, and 6.

Inclusion Criteria:

1. Outpatients ages 8-12 years (inclusive)
2. Currently meets DSM-IV (American Psychiatric Association, 1994) criteria for a primary diagnosis of ADHD (either predominantly inattentive type or combined type) based on the results of semi-structured diagnostic assessment (K-SADS-PL)(Kaufman et al., 1997) and based on the results of a clinical interview with a child and adolescent psychiatrist
3. Patients, who in the investigator's opinion, have substantial symptoms of ADHD for which pharmacotherapy is indicated
4. Has a guardian who has provided written informed consent to participate in this trial
5. Has provided written informed assent to participate in this study

Exclusion Criteria:

1. Patients who have a history of intolerance to APZ at a dose of 5 mg/day
2. Patients with a history of APZ allergy or hypersensitivity to APZ
3. Patients with an active or prior neurological/medical disorder for which treatment with APZ would be contraindicated (such as tardive dyskinesia or neuroleptic malignant syndrome)
4. Patients with clinical evidence of autistic disorder, Rett's syndrome or Asperger's syndrome
5. Patients with any bipolar spectrum disorder
6. Patients with any schizophrenia spectrum disorder
7. Patients with conduct disorder
8. Patients with post-traumatic stress disorder or generalized anxiety disorder
9. Patients with a substance abuse disorder
10. Females who are sexually active, pregnant or lactating
11. Patients with a suicide attempt requiring medical/psychiatric care within the past 6 months
12. Patient taking psychotropic agents within one week of baseline (3 days for psychostimulants, 2 weeks for fluoxetine)
13. Patients with evidence of mental retardation (I.Q. < 70) based on the results of the Peabody Picture Vocabulary Test- III (PPVT-III)(Dunn and Dunn, 1981)
14. Patients who have a general medical or neurological condition that could interfere with the interpretation of the clinical response to APZ treatment
15. Patients who are unable to swallow pills or capsules
16. Patients for whom the need for hospitalization during the course of the study appears likely