Samuel S. Kupietz

Alterations in the vigilance performance of children receiving amitriptyline and methylphenidate pharmacotherapy

The effects of amitriptyline (Elavil) and methylphenidate (Ritalin) on the vigilance of 20 hyperactive/aggressive children was investigated using an auditory version of the Continuous Performance Test (CPT). Over the course of this letter-detection task, correct detections tended to return to pretreatment levels under placebo, but were maintained at significantly improved levels under amitriptyline and methylphenidate.The relatively steep performance decrement which occurred in the placebo condition was found to be associated with a progressive increase in responses to the letter which immediately followed a target letter. Treating these ‘late’ responses as slow but ‘correct’ detections failed to eliminate the treatment effects obtained with amitriptyline and methylphenidate.It was concluded that in addition to keeping detection response latencies from increasing, the medications produced a heightened level of vigilance which resulted in an absolute increase in the number of correct detections.The facilitation of vigilance performance by amitriptyline was in apparent contradiction to reports by parents and teachers that children appeared ‘drowsy’ while receiving this medication. Findings of the study suggested that childrens ability to process information was unaffected by the reported side effect.

Psychostimulant plasma concentration and learning performance

Six normal adults were administered an oral dose of 0.25 mg/kg of dextroamphetamine, and their learning performance on a paired-associate task and drug blood level were measured at hourly intervals for 5 hours postdrug intake. Dextroamphetamine plasma concentration peaked at 2 to 3 hours following the oral dose, and learning errors were lowest during the same period. A self-report measure of mood also yielded findings consistent with peak plasma concentration. Similar findings obtained with hyperactive children treated with methylphenidate (Ritalin) lead the authors to conclude that the paired-associate learning task may be useful as an indicator of psychostimulant plasma levels, as a predictor of clinical response after an acute dose, and as a highly controlled task for studying psychostimulant drug effects on learning.

Attentiveness in behaviorally deviant and nondeviant children: I. Auditory vigilance performance.

The present study examined the vigilance performance of 16 behaviorally deviant and 16 nondeviant children and suggested that the vigilance paradigm might serve as a basis for a standardized test of continuous attention in children. The deviant and nondeviant children performed an auditory vigilance task administered on two separate occasions, 4 days apart. Performance during the first administration of the task deteriorated significantly for the deviant children as a function of time but not for the nondeviant ones. This finding was consistent with several prior clinical studies with children and suggested that the behaviorally deviant children were relatively less able to maintain a continuous level of attention. In addition, the vigilance procedure yielded relatively high test-retest reliability coefficients for both groups of children as well as performance which tended to vary as a function of chronological age.