Efficacy and Safety of Dex-Methylphenidate Extended Release 30 mg Versus 20 mg in Children (6-12 Years) With Attention-Deficit/Hyperactivity Disorder (ADHD) in a Laboratory Classroom Setting.

A Randomized, Multi-center, Double-blind, Placebo-controlled, Cross-over Study Evaluating the Safety and Efficacy of Dex-Methylphenidate Extended Release 30 mg vs. 20 mg as Measured by SKAMP-Combined Scores in Children With Attention-Deficit/Hyperactivity Disorder (ADHD) in a Laboratory Classroom Setting.

This study will evaluate the efficacy and safety of Dex-Methylphenidate Extended Release 30 mg compared to 20 mg in pediatric patients ages 6-12 with Attention-Deficit Hyperactivity Disorder (ADHD) in a 12-hour laboratory classroom setting.

Inclusion Criteria:

• Male and female subjects aged 6-12 years, inclusive.
• Subjects meeting the DSM-IV criteria for primary diagnosis of ADHD-Combined type, or predominantly hyperactive-impulsive subtype, as established by the K-SADS-PL (Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version). If a DSM-IV-defined ADHD diagnosis is difficult to establish due to possible co-morbidity, the subject will not be enrolled into the study.
• Subjects should be on a stabilized total daily dose or nearest equivalent of 40-60 mg methylphenidate or 20-30 mg of d-methylphenidate for at least two weeks prior to Screening visit.

Exclusion Criteria:

• Subject or subject's guardian unable to understand or follow instructions necessary to participate in the study.
• Diagnosed with or history of a tic disorder or Tourette's syndrome.
• History of seizure disorder.
• The presence of a known medical condition that would preclude the use of methylphenidate.
• A history (within the past year) or presence of clinically significant cardiovascular, cerebrovascular, renal, hepatic, gastrointestinal, pulmonary, immunological, hematological, endocrine, or neurological disease.
• ALT (Alanine Amino Transferase), AST (Aspartate Amino Transferase), GGT (Gamma glutamyl transferase) or serum creatinine greater then 2X the ULN (Upper Limit of Normal) at Screening.
• A history of psychiatric illness or substance use disorder (e.g., schizophrenia, bipolar disorder, autism, abuse or dependence, depression, severe Conduct Disorder or severe Oppositional defiant disorder)
• Subjects who have participated in an investigational trial within the past 4 weeks (28 days)
• Subjects who are currently taking antidepressants or other psychotropic medication.
• Subjects who have initiated psychotherapy during the three months prior to randomization.
• Subjects with a positive urine drug screen.
• Subjects who have a history of poor response or intolerance to methylphenidate or d-methylphenidate.

Other protocol-defined inclusion/exclusion criteria may apply