健康与遗传心理学研究室知识库

药物成瘾是一种慢性复发性脑疾病。成瘾行为的形成一般经历三个阶段:偶尔娱乐性使用药物、规律性习惯化使用药物、强迫性不可控地使用药物。冲动性在药物成瘾行为的形成过程中:药物使用的启动、维持、药物使用量的增加(失控)、戒断、复发等各阶段均起关键作用。高冲动性被认为是成瘾的核心行为标志物之一。但是由于冲动性的多维特性，何种结构的冲动对药物成瘾的形成发展起决定性作用尚未明确。目前国内外研究大多集中于探讨冲动性在成瘾行为发生、发展中的作用，将冲动性作为成瘾行为早期识别和干预的重要靶点，而较少研究成瘾行为形成后，在完全戒断时期内冲动性的变化状态及发展趋势。对于在戒毒所内进行强制隔离戒治的药物成瘾者来说，研究在完全戒断时期内冲动性的结构状态及发展趋势，对于戒毒管理、预防复吸等有重要意义。

成瘾行为戒断后，冲动性是否可逆取袂于成瘾药物的使用类型和剂量，及该类型的成瘾物质对大脑神经系统损伤的区域与程度。甲基苯丙胺(俗称冰毒)是目前我国最常见的滥用毒品之一，长期慢性使用会一导致中枢神经系统结构和功能的损害。本研究选用59名强制戒毒的甲基苯丙胺成瘾者为被试，通过为期4个月(第一次施测时间2015年8月15日左右，第二次施测时间2015年12月25日左右)的纵向追踪研究，采用问卷与行为任务相结合的研究方法，探讨不同戒断期甲基苯丙胺戒毒人员冲动性的变化。研究方法包括:1) UPPS-P测量被试特质性冲动;2)延迟折扣任务(DDT)、概率折扣任务(PDT)测量被试的冲动决策水平;3)停止信号任务(Stop signal >测量被试的dry动行为水平;4)情绪Stroop任务测量被试的认知能力控制。被试平均年龄24.5岁，教育年限7.9年，毒品成瘾程度分布如下:轻度2人，中度9人，重度48人。

本研究通过4个月间前后测的纵向研究考察甲基苯丙胺成瘾者冲动性与戒断时长的关系，研究结果如一卜:1)对前后两次测试的统计分析，发现被试三个冲动维度(特质冲动、认知冲动、行为冲动)均未发生显著性改变。2）但是在分组分析中发现，随着戒断时间的增加，短期戒断组(戒断时长<12个月)的特质型冲动(特别是正负性情绪下的冲动)表现出由低水平到高水平的改变，两个概率折扣任务反应的风险决策水平也都呈现出由低到高的显著性变化。3)长期戒断组(戒断时长≥12个月)的特质型冲动(特别是正负性情绪下的冲动)则随着戒断时间的增加，表现出由高水平到低水平的改变，而状态型冲动(包括行为冲动和认知冲动)的前后对比均未发现显著性差异。

通过横向研究，我们探讨了冲动维度受何种毒品成瘾严重程度指标的影响更深，结果发现: 1）特质冲动受吸毒量、诊断评估分数的影响最大，高吸食量组、高诊断评估分数组的特质冲动显著增强; 2)认知冲动下受吸毒量、诊断评估分数的影响最大，高吸食量组、高诊断评估分数组.的认知冲动存在显著增强; 3)注意偏向(认知控制能力)受吸毒时长影响最大，长吸毒时长组的冲动性存在显著增强。在完全戒断期内，戒断时长对认知冲动这一维度有负向预测作用，与其他冲动维度无显著相关性。

纵向研究和横向研究的结果表明，甲基苯丙胺成瘾者不同冲动维度与吸毒量、吸毒时长、诊断评估分数三个毒品成瘾严重程度指标相关;戒断时一长仅对认知冲动存在负向预测作用，即仅认知冲动水平会随戒断时间的增加而降低;在实验截取的4个月内，被试的特质型冲动和状态型冲动均未出现显著性变化。

以上研究结果y!结论对于我们实际工作的指导意义在于: 1、我国采取强制隔离戒毒措施有其必要性和可行性。2、对行为冲动的干预和矫治应成为强制隔离戒毒期的工作重点。3、与毒品成瘾严重程度相关的冲动类型可作为戒治初期分类戒治、分型编队的依据。4、对冲动水平的干预应及早进行。

addiction is a chronic recurrent brain disease. It develops spirally with three stages: occasionally recreational use, regularly routine use and finally compulsive drug use out of control-studies indicated that impulsivity plays a key role in all phases of the development of drug addiction from the initiation, maintenance and escalation(out of control),abstinence to relapse. High impulsivity is considered to be one of the key behavioral markers of addiction Due to the multidimensional characteristics of impulsivity, it is not clear that which dimension of the impulsivity is crucial for the development of drug addiction. The previous studios paid much attention to the role of impulsivity in the initiation and formation of addiction, and the impulsivity is identified as the core targets for early detection and intervention. However, few studies examined the changing trajectories of different dimension of impulsivity at the different time points during abstinence periods. Characterizing the impulsivity feature and changing trajectory, will help a lot in management of drug treatment and relapse prevention for those whom are being compulsorily isolated for detoxification in the drug rehabilitation center.

During abstinence, the magnitude of recovery of impulsive behaviors is dose-dependent on the types of the drug use, since different addictive drugs may cause the dysfunctions in different brain areas. Methamphetamine (MA, commonly known as crystal meth) is the most popularly and commonly used drug in china. Long-term chronic use can lead to deficits on the structure and function of the central nervous system. longitudinal study was launched in the present study with 59 MA addicts at different abstinence periods, to study the changing trajectories of impulsivity. The first test was ground l-august 15th, 2015 end the second test teas done 4 months Inter. All the tests on impulsivity are as follows: 1)UPPS-P to test the trait impulsivity; 2) Delay Discounting Tasks (DDT) and Probability of Discounting Tasks (PDT) were used to test the impulsive decision; 3) Stop Signal was used to test impulsive behavior; 4) Words emotional Stroop Task was used to test the level of cognitive control.

The subjects are X4.5 years old by average and the average education time is about 7.9 years, and the severity of addiction was assessed by DSM-5. All subjects were classified as 3 categories, mild(n=2), moderate(n=9) and heavy(n=48) addicts respectively. The present study explored the relation between impulsivity and duration of abstinence in methamphetamine addicts through longitudinal studies. It was found that there was no significant change in any of the three dimensions of impulsivity (trait impulse, impulsive behavior, cognitive impulse) between the pretest and the post test four months later. However, the situation is different in short-term abstinence group (STA, duration of abstinence <12 months) and long-term abstinence group (LTA, duration of abstinence >12 months). Specifically, in STA group, the trait impulsivity enhances as the duration of abstinence increases and the cognitive impulsivity also enhances as the abstinence lasts which was revealed by the results of DDT and PDT. In the LTA group, with the extension of abstinence, trait impulsivity decreases significantly, while no significant change was detected between the pretest and the post Lost in impulsive behavior and cognitive impulsivity.

With the data collected from the post test, cross-sectional analysis was conducted to investigate the relation between impulsivity and the severity of MA addiction, and recoverability of the three dimensions of impulsivity in the complete withdrawal period were also explored. The results showed a positive correlation of trait impulse, impulsive behavior and cognitive impulse with the severity of MA addiction which was revealed by the cumulative dosage of drug consumption and the duration of abuse. Besides, duration of abstinence can negatively predict the level of cognitive impulse, but has no significant correlation with the other two dimensions of impulse.

In conclusion, the present study found that the level of impulse in MA addicts is positively correlated with the severity of MA addiction. And the duration of abstinence can negatively predict the level of cognitive impulse.

The above research results and conclusions suggested the necessity of the compulsive isolation detoxification in our country. And the intervention and treatment of impulse in MA addicts should be the focus of our work and carried out early during abstinence. Besides, MA addicts could be classified according to the level of impulsivity for further treatment and management.