|其他题名||A comparison of cognitive and neural mechanisms between heroin dependence and pathological gambling: Reward processing and cognitive control in addiction|
|关键词||海洛因成瘾 病理性赌博 奖赏决策 抑制控制 功能性磁共振成像|
|其他摘要||Research on the underlying mechanisms of drug addiction is crucial to its prevention and treatment. Previous studies have implied that both individual susceptibility and neurotoxicity of drugs may be involved in the development of drug addiction and the confusion effect of these factors has been an obstacle to studying the mechanisms of drug addiction. As a non-substance induced behavioral addiction formally included in the DSM-V, pathological gambling (PG) shares many similarities with drug addiction. However, PG does not involve the neurotoxicity associated with drug use, thus it offers an opportunity to study the mechanisms of addiction without drug-related effects. It is believed that a comparison of PG and drug addiction may help dissociate the specific effects of chronic drug use from the vulnerabilities that predispose addiction.|
Recently the dual-system theories of addiction have paid much attention on the reward/affective system (e.g. vmPFC, OFC, insula, amygdala, striatum) and the cognitive control/reflective system (e.g. dlPFC, ACC, IFG), which functioning may be disrupted in addiction. However, whether these two systems are disrupted in both PG and drug addiction is unclear.
In the present study, neurocognitive aspects of pathological gamblers (PGs), heroin addicts (HAs) and a group of age-, sex-, and education-matched healthy controls were assessed by well-constructed neuropsychological tasks. In Study 1, affective decision-making was measured by the Iowa Gambling Task (IGT), risk-taking behavior was assessed by the Balloon Analogue Risk Task (BART), and reward/punishment sensitivity was assessed using the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SRSPQ). In Study 2, working memory was assessed using the Self-ordered Pointing Test (SOPT), and reversal learning was measured by the Reversal Learning Task (RLT). Moreover, functional magnetic resonance imaging (fMRI) was used to investigate the neural circuitry associated with impaired reward-based/ affective decision-making in the IGT (Study 3) and response inhibition in the Go/No Go task (Study 4) among PGs and HAs compared with controls.
The results showed that: (1) both PGs and HAs showed significant deficits in affective decision-making, guided by immediate prospects, oblivious to future consequences, and years of heroin use were correlated negatively with decision-making performance in heroin addicts; (2) deficits in working memory and reversal learning were also detected in HAs, with longer duration of heroin use associated with more severe working memory deficits, while PGs showed non-impaired performance on working memory and reversal learning; (3) Has showed hyporesponsiveness of the medial prefrontal cortex and the anterior cingulate gyrus compared to healthy controls during experiencing reward outcome (win money), and both PGs and HAs showed hyporesponsiveness of the orbital frontal cortex and the insular cortex during experiencing punishment outcome (lose money) in the IGT; (4) HAs showed hyporesponsiveness of the dorsolateral prefrontal cortex during response inhibition in the Go/No Go task, while PGs did not show hyporesponsiveness of the dorsolateral prefrontal cortex during response inhibition compared to controls.
Our findings indicate that heroin dependence is characterized by deficits of the reward/affective system and the cognitive control/reflective system, implying a dual-disordered neurophysiological model of addiction, by contrast, PG is associated with impairments in the reward/affective system, especially the circuitry connected to negative affects such as loss. Deficits of the affective system may thus serve as one common neural mechanism of HA and PG.
|严万森. 海洛因成瘾与赌博成瘾的认知神经机制比较研究：奖赏加工和认知控制在成瘾中的作用及其机制[D]. 北京. 中国科学院研究生院,2013.|
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