Solanto M V, Wender E H, Bartell S S
Division of Child and Adolescent Psychiatry, Schneider Children's Hospital, Long Island Jewish Medical Center, New Hyde Park, New York, USA.
J Child Adolesc Psychopharmacol. 1997 Summer;7(2):123-36. doi: 10.1089/cap.1997.7.123.
Psychostimulants and behavior therapy have been postulated to be effective in treating attention-deficit hyperactivity disorder (ADHD) by compensating for a pathologically elevated reward threshold, but no studies have compared reinforcement to psychostimulants in maintaining task performance. The separate and combined effects of methylphenidate (MPH, 0.6 mg/kg) and a behavioral intervention (reward plus response cost) were assessed on a continuous performance test (CPT, a measure of sustained attention) modified to deliver auditory feedback contingent upon the subject's responses. Each of 22 children (6-10 years old) with ADHD were tested under four treatment conditions: placebo + feedback, placebo + behavioral contingencies, MPH + feedback, and MPH + contingencies. CPT performance, indexed by d' (ability to discriminate between target and false targets), was significantly better with MPH than with placebo, showing reduced deterioration over time. Contingency treatment improved mean d' compared to placebo + feedback but, in contrast, had no effect on the slope of performance deterioration. Addition of contingencies to MPH did not yield further improvement. The results indicate that MPH improved sustained attention on a laboratory task (and reduced task-irrelevant and other disinhibited behaviors), whereas behavioral contingencies did not. These findings suggest that, although both interventions improved stimulus discrimination processes, only MPH enhanced processes that mediate the regulation of effort over time. In addition, the disjunction between the effects of reward and of MPH provides evidence that psychostimulant effects on attention are only partially explained by the stimulation of brain centers associated with reward.
精神兴奋剂和行为疗法被假定可通过补偿病理性升高的奖励阈值来有效治疗注意力缺陷多动障碍（ADHD），但尚无研究比较强化疗法与精神兴奋剂在维持任务表现方面的效果。本研究评估了哌甲酯（MPH，0.6毫克/千克）和行为干预（奖励加反应代价）单独及联合使用时，对一项经过改良的连续性能测试（CPT，一种持续注意力的测量方法）的影响，该测试根据受试者的反应提供听觉反馈。22名患有ADHD的儿童（6 - 10岁）在四种治疗条件下接受测试：安慰剂 + 反馈、安慰剂 + 行为意外情况、MPH + 反馈以及MPH + 意外情况。以d'（区分目标与错误目标的能力）为指标的CPT表现，使用MPH时显著优于使用安慰剂，且随时间推移恶化程度降低。与安慰剂 + 反馈相比，意外情况治疗改善了平均d'，但与之相反，对表现恶化的斜率没有影响。在MPH基础上增加意外情况并未带来进一步改善。结果表明，MPH改善了在实验室任务中的持续注意力（并减少了与任务无关及其他抑制解除行为），而行为意外情况则没有。这些发现表明，尽管两种干预都改善了刺激辨别过程，但只有MPH增强了随着时间推移调节努力的过程。此外，奖励与MPH效果之间的差异提供了证据，表明精神兴奋剂对注意力的影响仅部分可由与奖励相关的脑中心的刺激来解释。
