The Influence of Methylphenidate on Spontaneous Autonomic Activity and Behavior in Children Diagnosed as Hyperactive.

Methylphenidate influenced the spontaneous autonomic activity of children diagnosed as hyperactive. There was dose response related reduction in disruptive classroom behavior monitored by the teacher ratings and a parallel decrease in a component of heart period variability, &Vcirc;, derived via spectral analysis of heart period activity. A low dose of methylphenidate, which has been reported to enhance cognitive performance, selectively increased a measure of respiratory-cardiac coupling, Cw, derived via cross-spectral analysis of respiration and heart period activity. It is hypothesized that Cw may be a quantitative manifestation of brainstem integration and &Vcirc; may be a quantitative estimate of effective vagal tone on the heart. [ABSTRACT FROM AUTHOR]