BACKGROUND Chronic cocaine use is associated with structural brain abnormalities within prefrontal regions implicated in impulsivity. Despite high levels of impulsivity among persons who use cocaine, it is not known how reductions in gray matter volume (GMV) may relate to trait and behavioral measures of impulsivity. METHODS The sample included 39 active cocaine users (COC+) and 40 controls with no history of cocaine use (COC-). Participants had a brain scan on a 3 T MRI machine and completed out-of-scanner measures of trait impulsivity and delayed reward discounting. Whole-brain voxel-based morphometry was used to compare GMV between COC+ and COC-. Within regions that differed between groups, voxelwise correlations were conducted to examine the relationship between GMV and impulsivity. RESULTS In a whole-brain analysis, COC+ had broad reductions in GMV compared to COC- in bilateral frontal, parietal, occipital, and cerebellar regions. Lower GMV correlated with trait impulsivity in lateral prefrontal regions and with delayed reward discounting in medial prefrontal regions, while lower GMV correlated with both measures in the posterior parietal cortex. COC+ demonstrated significantly higher impulsivity than COC- on all measures, but the nature of the correlation with GMV was similar in both groups. CONCLUSIONS Reflecting the multi-faceted nature of impulsivity, these results show that trait and behavioral measures of impulsivity map differentially onto altered brain morphology. While the brain-behavior patterns were similar in COC+ and COC-, suggesting that impulsivity varies on a continuous spectrum, cocaine-related abnormalities in frontal-parietal brain systems may contribute to heightened impulsivity.

中文翻译：

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可卡因相关的额顶叶灰质体积变化与特质和行为冲动相关。


背景技术长期使用可卡因与冲动性前额叶区域的大脑结构异常有关。尽管使用可卡因的人冲动性很高，但目前尚不清楚灰质体积（GMV）的减少与冲动性的特征和行为测量有何关系。方法 样本包括 39 名活跃可卡因使用者 (COC+) 和 40 名无可卡因使用史的对照者 (COC-)。参与者在 3 T MRI 机器上进行了脑部扫描，并完成了扫描仪外的特质冲动和延迟奖励折扣测量。使用基于全脑体素的形态测量来比较 COC+ 和 COC- 之间的 GMV。在组间不同的区域内，进行体素相关性来检查 GMV 和冲动之间的关系。结果 在全脑分析中，与 COC- 相比，COC+ 在双侧额叶、顶叶、枕叶和小脑区域的 GMV 大幅降低。较低的 GMV 与外侧前额叶区域的特质冲动性和内侧前额叶区域的延迟奖励折扣相关，而较低的 GMV 与后顶叶皮层的这两项指标相关。在所有指标上，COC+ 的冲动性均显着高于 COC-，但两组与 GMV 的相关性性质相似。结论 这些结果反映了冲动的多面性，表明冲动的特征和行为测量以不同的方式映射到改变的大脑形态上。虽然 COC+ 和 COC- 的大脑行为模式相似，表明冲动性在连续范围内变化，但额叶-顶叶大脑系统中与可卡因相关的异常可能会导致冲动性增强。