Potter Alexandra S, Newhouse Paul A
Clinical Neuroscience Research Unit, Department of Psychiatry, College of Medicine, University of Vermont, 1 South Prospect Street, Burlington, VT 05401, USA.
Psychopharmacology (Berl). 2004 Nov;176(2):182-94. doi: 10.1007/s00213-004-1874-y. Epub 2004 Apr 9.
Adolescents with attention-deficit/hyperactivity disorder (ADHD) become cigarette smokers at twice the rate of non-ADHD adolescents, and this finding continues into adulthood. Abnormal cognitive/behavioral inhibition is one core cognitive symptom of ADHD, leading to impulsive behavior in people with this disorder. Nicotine, contained in tobacco smoke, is known to improve attention, vigilance, and short-term memory. However, little is known about how nicotine might effect cognitive/behavioral inhibition.
This study tested the hypothesis that acute nicotine administration would improve cognitive/behavioral inhibition in non-smoking adolescents with ADHD.
This single-dose, acute, repeated-measures, double blind study in adolescents (13-17 years) with DSM-IV confirmed ADHD assessed the effects of transdermal nicotine, oral methylphenidate, and placebo on inhibition in non-smoking adolescents with ADHD. Dependent measures included tests of cognitive/behavioral inhibition (the stop signal task), cognitive interference control (the Stroop task), and a measure of verbal learning and recognition (the hi-low imagery task).
Results from five subjects indicated that stop signal reaction time (SSRT), an estimate of the speed of inhibiting a response, was significantly (P<0.01) improved following both nicotine and methylphenidate treatment as compared to placebo treatment. Neither "go" reaction time nor accuracy showed any effect of drug. In the Stroop task, another task of cognitive inhibition, nicotine but not methylphenidate significantly (P<0.05) decreased the Stroop effect compared to placebo.
These results indicate that nicotine administration has measurable positive effects on cognitive/behavioral inhibition in adolescents with ADHD. The size of the effect is at least comparable to methylphenidate. Positive effects of nicotine on inhibitional performance may contribute to higher rates of cigarette use in adolescents with ADHD.
患有注意力缺陷多动障碍（ADHD）的青少年开始吸烟的几率是非ADHD青少年的两倍，且这一现象会持续到成年期。异常的认知/行为抑制是ADHD的一个核心认知症状，会导致该疾病患者出现冲动行为。烟草烟雾中含有的尼古丁已知可改善注意力、警觉性和短期记忆。然而，关于尼古丁如何影响认知/行为抑制却知之甚少。
本研究检验了以下假设，即急性给予尼古丁会改善患有ADHD的非吸烟青少年的认知/行为抑制。
这项针对确诊患有DSM-IV标准ADHD的青少年（13 - 17岁）的单剂量、急性、重复测量、双盲研究，评估了经皮尼古丁、口服哌甲酯和安慰剂对患有ADHD的非吸烟青少年抑制能力的影响。相关测量指标包括认知/行为抑制测试（停止信号任务）、认知干扰控制测试（斯特鲁普任务）以及言语学习和识别测量（高低意象任务）。
五名受试者的结果表明，与安慰剂治疗相比，尼古丁和哌甲酯治疗后，作为抑制反应速度估计值的停止信号反应时间（SSRT）显著改善（P<0.01）。“继续”反应时间和准确性均未显示出药物的任何影响。在另一个认知抑制任务即斯特鲁普任务中，与安慰剂相比，尼古丁而非哌甲酯显著（P<0.05）降低了斯特鲁普效应。
这些结果表明，给予尼古丁对患有ADHD的青少年的认知/行为抑制有可测量的积极影响。这种影响的程度至少与哌甲酯相当。尼古丁对抑制表现的积极影响可能导致患有ADHD的青少年吸烟率较高。
