Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Center for Functional Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom.
Drug Alcohol Depend. 2021 Feb 1;219:108483. doi: 10.1016/j.drugalcdep.2020.108483. Epub 2020 Dec 29.
Methadone maintenance treatment (MMT) is effective in decreasing opioid use or facilitating abstinence. Previous studies using small opioid use disorder samples suggest that cognitive impairments including impulsivity and executive functions may partially improve on MMT, but a range of deficits may persist. However, systematic assessments with larger samples are needed to confirm the profile of cognitive functions on MMT.
We assessed four types of impulsivity (delay discounting, reflection impulsivity, risk taking and motoric impulsivity), executive functioning (spatial working memory, paired associative learning and strategic planning) and drug cue-induced craving in a relatively large population (115 MMT patients, 115 healthy controls). The relationships between impulsivity, drug cue-induced craving and addiction-related variables were also assessed.
Delay discounting, as well as drug cue-induced craving was increased in patients, while motoric impulsivity was lower than in controls. Paired associative learning was additionally impaired, which was explained by increased depression and anxiety levels in patients. Within the MMT group, the delay discounting and drug-cue induced craving scores were positively correlated with self-reported urgency, but unrelated to methadone dosage, duration on methadone, withdrawal symptoms, or presence of nicotine dependence.
Our findings highlight increased delay discounting and cue-induced craving in MMT patients suggesting a potential role for trait effects in delay discounting. Although previous smaller studies have shown impaired executive function, in our large sample size on chronic MMT we only observed impaired associative learning related to depressive and anxiety symptoms highlighting a role for managing comorbid symptoms to further optimize cognitive function.
美沙酮维持治疗（MMT）在减少阿片类药物使用或促进戒断方面是有效的。之前的研究使用小样本的阿片类药物使用障碍表明，认知缺陷，包括冲动和执行功能，可能会部分改善 MMT，但可能会持续存在一系列缺陷。然而，需要用更大的样本进行系统评估，以确认 MMT 上的认知功能特征。
我们评估了四种类型的冲动性（延迟折扣、反射冲动、冒险和运动冲动）、执行功能（空间工作记忆、成对联想学习和策略规划）和药物线索引起的渴求在相对较大的人群中（115 名 MMT 患者，115 名健康对照者）。还评估了冲动性、药物线索引起的渴求与成瘾相关变量之间的关系。
与对照组相比，患者的延迟折扣和药物线索引起的渴求增加，而运动冲动性较低。配对联想学习也受到损害，这可以用患者中抑郁和焦虑水平的增加来解释。在 MMT 组中，延迟折扣和药物线索引起的渴求评分与自我报告的紧迫性呈正相关，但与美沙酮剂量、美沙酮使用时间、戒断症状或尼古丁依赖无关。
我们的研究结果强调了 MMT 患者的延迟折扣和线索引起的渴求增加，这表明冲动性的特质因素可能起作用。尽管之前的较小研究表明执行功能受损，但在我们对慢性 MMT 的大样本量研究中，我们只观察到与抑郁和焦虑症状相关的联想学习受损，这突出了管理共病症状以进一步优化认知功能的作用。
