Division of Population and Behavioural Science,School of Medicine, St Andrews University,St Andrews, Fife,UK.
School of Medicine (Neuroscience), Ninewells Hospital & Medical School, University of Dundee,Dundee, Tayside,UK.
Psychol Med. 2019 May;49(7):1174-1184. doi: 10.1017/S0033291718003318. Epub 2018 Nov 20.
Chronic opioid exposure is common world-wide, but behavioural performance remains under-investigated. This study aimed to investigate visuospatial memory performance in opioid-exposed and dependent clinical populations and its associations with measures of intelligence and cognitive impulsivity.
We recruited 109 participants: (i) patients with a history of opioid dependence due to chronic heroin use (n = 24), (ii) heroin users stabilised on methadone maintenance treatment (n = 29), (iii) participants with a history of chronic pain and prescribed tramadol and codeine (n = 28) and (iv) healthy controls (n = 28). The neuropsychological tasks from the Cambridge Neuropsychological Test Automated Battery included the Delayed Matching to Sample (DMS), Pattern Recognition Memory, Spatial Recognition Memory, Paired Associate Learning, Spatial Span Task, Spatial Working Memory and Cambridge Gambling Task. Pre-morbid general intelligence was assessed using the National Adult Reading Test.
As hypothesised, this study identified the differential effects of chronic heroin and methadone exposures on neuropsychological measures of visuospatial memory (p < 0.01) that were independent of injecting behaviour and dependence status. The study also identified an improvement in DMS performance (specifically at longer delays) when the methadone group was compared with the heroin group and also when the heroin group was stabilised onto methadone. Results identified differential effects of chronic heroin and methadone exposures on various neuropsychological measures of visuospatial memory independently from addiction severity measures, such as injecting behaviour and dependence status.
慢性阿片类药物暴露在全球范围内很常见，但行为表现仍未得到充分研究。本研究旨在调查阿片类药物暴露和依赖的临床人群的视空间记忆表现及其与智力和认知冲动性测量指标的关系。
我们招募了 109 名参与者：（i）因慢性海洛因使用而有阿片类药物依赖史的患者（n=24），（ii）稳定接受美沙酮维持治疗的海洛因使用者（n=29），（iii）有慢性疼痛病史并开处方曲马多和可待因的参与者（n=28）和（iv）健康对照者（n=28）。剑桥神经心理学测试自动化电池中的神经心理学任务包括延迟匹配样本（DMS）、模式识别记忆、空间识别记忆、配对联想学习、空间跨度任务、空间工作记忆和剑桥赌博任务。预先确定的一般智力通过国家成人阅读测试进行评估。
正如假设的那样，本研究确定了慢性海洛因和美沙酮暴露对视空间记忆神经心理学测量的不同影响（p < 0.01），这些影响独立于注射行为和依赖状态。该研究还发现，与海洛因组相比，美沙酮组的 DMS 表现（特别是在较长的延迟时间内）有所改善，而海洛因组在稳定到美沙酮时也有所改善。结果确定了慢性海洛因和美沙酮暴露对各种视空间记忆神经心理学测量的不同影响，独立于成瘾严重程度测量指标，如注射行为和依赖状态。
