Schachar R, Tannock R
J Child Adolesc Psychopharmacol. 1993 Summer;3(2):81-97. doi: 10.1089/cap.1993.3.81.
ABSTRACT Clinical trials with a treatment duration of at least 3 months were reviewed to determine the effect of psychostimulants on the core symptoms of attention-deficit hyperactivity disorder (ADHD) and on its commonly associated features. Eighteen studies were identified: 17 were studies of methylphenidate, 1 was a study of dextroamphetamine, and none involved pemoline or slow-release stimulants. Eleven of these studies were randomized controlled trials, whereas seven employed quasi-experimental designs without randomization. The results of randomized controlled trials showed that psychostimulants provided greater benefit than did the nonrandomized trials, suggesting that the efficacy of extended treatment may have been underestimated because more seriously disturbed children were assigned to medication treatment than to control treatments in nonrandomized trials. Evidence from the more definitive randomized controlled trials indicates that stimulants are more effective in ameliorating the core behavioral symptoms of ADHD (restlessness, inattentiveness, impulsiveness) than placebos, nonpharmacological therapies, or no treatment-at least in 3-7-month trials. During extended psychostimulant treatment, few children become symptom-free, clinical effects may diminish with time, and improvement dissipates rapidly upon discontinuation of medication. There is minimal evidence that extended stimulant treatment improves cognitive deficits or associated problems such as conduct disturbance, low self-esteem, poor peer relationships, or academic underachievement. The belief that stimulants do not improve the long-term prognosis of children with ADHD may be based on weakly designed studies that focus on associated rather than core symptoms. A failure to assign patients of similar clinical severity to different treatment conditions may also have contributed to obscuring the efficacy of extended psychostimulant treatments.
对治疗时长至少为3个月的临床试验进行了综述，以确定精神兴奋剂对注意力缺陷多动障碍（ADHD）核心症状及其常见相关特征的影响。共识别出18项研究：17项是关于哌甲酯的研究，1项是关于右旋苯丙胺的研究，没有涉及匹莫林或缓释兴奋剂的研究。其中11项研究为随机对照试验，7项采用非随机的准实验设计。随机对照试验的结果表明，精神兴奋剂比非随机试验更具疗效，这表明长期治疗的疗效可能被低估了，因为在非随机试验中，分配到药物治疗组的儿童比对照组的儿童病情更严重。来自更具权威性的随机对照试验的证据表明，在至少3至7个月的试验中，兴奋剂在改善ADHD的核心行为症状（多动、注意力不集中、冲动）方面比安慰剂、非药物疗法或不治疗更有效。在长期使用精神兴奋剂治疗期间，很少有儿童症状完全消失，临床疗效可能会随时间减弱，停药后改善情况会迅速消失。几乎没有证据表明长期使用兴奋剂治疗能改善认知缺陷或相关问题，如品行障碍、自卑、同伴关系差或学业成绩不佳。认为兴奋剂不能改善ADHD儿童长期预后的观点可能基于设计薄弱的研究，这些研究关注的是相关症状而非核心症状。未能将临床严重程度相似的患者分配到不同的治疗组，也可能导致长期使用精神兴奋剂治疗的疗效难以显现。
