药物成瘾对决策行为的损伤及戒断后的恢复

Impairment of Drug Addiction on Decision Making and Recovery after Abstinence

目的:本研究采用赌博任务考察不同戒断时长的药物戒断者(短期戒断组:平均2.7个月,中期戒断组:平均19.4个月,长期戒断组:平均49.6个月),行为决策能力的损伤与恢复情况。方法:实验中要求药物戒断者与正常控制组完成赌博任务,被试根据屏幕所示的概率判断目标出现在屏幕的左边还是右边。结果:行为结果发现,所有戒断组赌博得分均低于控制组,说明药物戒断者的行为具有高冲动性;中期组和长期组的赌博得分在实验的中期、后期均显著高于实验的前期,表明随着戒断时间延长,药物成瘾对学习能力产生的损伤逐渐恢复。脑电结果发现,面对不同类型的赌博界面,短期组和中期组均未显示出N2波的差异,而长期组能够区分Pass类型与Gamble类型,以及Pass类型与Nogo类型,但是区分的方向与控制组相反,说明药物对长期戒断者决策偏好、选择能力的损伤并未完全恢复。结论:药物成瘾者的行为决策偏好、选择能力和执行控制能力都存在损害,戒断4年后的长期组决策能力有所恢复,但仍未恢复至正常水平。

Objective： Using a gamble task, the aim of the study is to explore the impairment and recovery of decision making in patients with drug addiction. We measured, the different ERP activities in abstainers with different abstinent- terms（short-term group： mean=2.7 months, middle-term group： mean=19.36 months, long-term group： 49.6 months） and healthy control participants. Methods： Participants were required to identify the position of target on the left or the right of the screen according to the probability. Results： Behavioral data showed that all abstainers acquired lower gambling scores than control group, indicating that the behavior of all abstainers have higher impulsivity compared to control. And gambling scores acquired by short-and middle-term groups significantly increased in the middle and late stages of the experiment compared to the early stage. This suggest sthat the decline of study ability gradually recovered with the withdrawal time prolonged. Electroencephalographic（EEG） results found that the short-and middle-term groups had no difference in N2 amplitude, and that long-term group showed similar but not identical pattern of brain activation compared to control group. Conclusion： Drugs impair the ability of information-analysis and executive control. This damage seems to be recovered after four years withdrawal in long-term group, but not returned to normal levels yet.