Objectives: To evaluate the pharmacodynamic effects of an experimental (EXP) delivery of methylphenidate (MPH) in children with attention-deficit/hyperactivity disorder and to investigate the situational nature of effects in laboratory classroom and playground settings.
Method: A "sipping" study methodology was used to deliver a bolus followed by small but increasing MPH doses as the EXP regimen. A randomized, double-blind crossover design was used to compare the EXP regimen to a thrice-daily (TID) regimen and a placebo (PLA) regimen. Measures of efficacy were obtained from a Motionlogger actigraph to quantify activity and from the Swanson, Kotkin, Agler, M-Flynn, and Pelham (SKAMP) rating scale to quantify two domains of behavior (attention and deportment).
Results: Compared with PLA, both EXP and TID delivery of MPH produced large, significant reductions in activity and inappropriate behavior in the classroom, but the two MPH regimens did not differ in onset or duration of effects across the day. The MPH effects were situationally dependent and were smaller for the playground than for the classroom settings.
Conclusions: The findings of this "proof of concept" study support the efficacy of a continuous, ascending delivery of MPH. The situational effects of MPH provide support for the theory of selective effects of stimulants, dependent on the demands of the environment.