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Abstract. In this study we analyzed some of the cognitive components that may constitute attention deficit disorder. It consisted of a double-blind, drug-placebo study of 12 children being treated with three doses of methylphenidate and placebo. Results of an attentional test battery, teacher and parent ratings, and blood levels of methylphenidate are reported. In general, performance was best with 0.6 mg/kg of methylphenidate (the highest dose tested) and worst with placebo. It is argued that no single test provides a complete assessment of attentional deficits and that methylphenidate can improve performance by affecting the allocation of cognitive resources to a task. [ABSTRACT FROM AUTHOR]

Abstract. Despite the frequent use of methylphenidate (MPH) in school-aged children with disorders of attention, impulsivity, and activity regulation (attention deficit disorder, ADD), little is known of its clinical pharmacology. The pharmacokinetics of MPH as well as its effects on growth hormone and prolactin were examined after oral administration in 14 boys with ADD ranging in age from 7 to 12 years (mean 10.4 years). Peak concentrations determined in these acute studies were compared with concentrations obtained two hours after MPH administration in another group of children with ADD who were receiving MPH chronically. After a lag phase of approximately 1/2 to 1 hour, MPH reached a peak plasma concentration at 2.5 +/- 0.65 hours after 0.34 mg/kg and 1.9 +/- 0.82 hours after 0.65 mg/kg (mean +/- SD). Terminal half-lives were 2.53 +/- 0.59 and 2.61 +/- 0.29 hours after administration of 0.34 and 0.65 mg/kg, respectively. Observed maximal concentrations ranged from 11.2 +/- 2.7 ng/ml after administration of 0.34, and 20.2 +/- 9.1 ng/ml after administration of 0.65 mg/kg. The mean area under the curve after administration of 0.65 mg/kg was approximately double that calculated at 0.34 mg/kg. Plasma growth hormone increased significantly from an initial (pre-MPH) mean concentration of 4.4 to peak at two hours at 10.5 ng/ml. Prolactin concentration declined significantly from a pre-MPH level of 9.5 to a nadir at 1 1/2 hours of 3.80 ng/ml, supporting the notion that MPH is acting via central dopaminergic mechanisms. MPH concentratious in children receiving doses of 0.34 mg/kg chronically averaged 8.00 +/- 0.91 at two hours, after medication, approximating the mean concentration at the same time observed in the acute study. The concentration of MPH in single "spot" samples obtained at two to three hours after administration of medication were significantly correlated with the percentage of improvement in the abbreviated Conners rating scale, indicating a rela... [ABSTRACT FROM AUTHOR]

Discusses some of the pitfalls in clinical research in attention deficit disorder (ADD) in children. Issue posed by the definition of the disorder; Diagnostic criteria of ADD; Assessment of pharmacotherapy for the disorder; Failure to consider other management procedures for ADD.