A Long Term Post-Marketing Study on the EffIcacy and Safety of Osmotic Release Oral System (OROS) Methylphenidate on the Cognitive Functions of Attention Deficit Hyperactivity Disorder (ADHD) Participants

The purpose of this long term post-marketing study is to evaluate the effectiveness and safety of osmotic release oral system methylphenidate hydrochloride (OROS-MPH) in participants with Attention Deficit Hyperactivity Disorder (ADHD).

This is an open-label (all people know the identity of the intervention), prospective (study following participants forward in time), self-controlled, long-term post-marketing study in participants with ADHD. The study consists of 3 periods: screening period, wash-out period/run-in period (3 days), and open-label treatment period (12 weeks) which is divided into 2 periods that is dosage adjustment period and dose-optimization period. The total duration of the study is 12 weeks. During the dosage adjustment period, the dose of methylphenidate hydrochloride was adjusted to the optimal dose within 1-3 weeks starting with initial dosage of 18 milligram per day (mg/d) which can be increased to 36 mg/d up to a maximum dosage of 54 mg/d according to the therapeutic effect and tolerance or maintained at 36 mg or re-adjusted to 18 mg due to intolerance. Participants will receive the optimal dose determined during dose adjustment period for 9 weeks during the dose-optimization period. In the study, 2 types of participants will be enrolled in 2 groups (according to condition): OROS-MPH group (participants with ADHD) and the normal children group (healthy participants). The efficacy will be assessed primarily by Digit Span Test and Inattention /Over activity With Aggression (IOWA) Conners evaluation scale. Participants' safety will be monitored throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* ADHD children must sign the consent form in person, and their parents or guardian must endorse, in the consent form, participation of the child in the designated research program
* Through personal interaction and assessment questionnaire, examine to determine compliance of DSM-IV ADHD diagnostic criteria
* According to the judgment of researchers, the ADHD children should have normal intelligence. Normal intelligence is defined as no obvious evidence of mental retardation in general (specific learning disabilities will not be considered mental retardation in general), formal IQ test to be conducted and 85 marks or above ought to be scored
* ADHD children should not have been subjected to psychotropic drug treatment within 6 months. Those ADHD children on whom methylphenidate immediate-release tablets treatment is effective (with maximum daily dosage of 60 mg), may be admitted
* Normal children with IQ greater than or equal to 85

Exclusion Criteria:

* Unable to fully comply with the cognitive function test in the laboratory
* Known to be allergic to methylphenidate
* Consumption of psychoactive drugs currently or in the past 30 days, including use of monoamine oxidase inhibitors, clonidine, other alpha 2 adrenergic receptor agonists, tricyclic antidepressants, theophylline, bishydroxycoumarin etc
* History of alcohol, drugs or substances abuse
* Have medical history of type I or II bipolar affective disorder, anxiety disorder, schizophrenia or pervasive developmental disorder