Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada.
Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
Eur J Neurosci. 2017 Oct;46(7):2253-2264. doi: 10.1111/ejn.13661. Epub 2017 Sep 4.
Impulsivity is considered a vulnerability trait for addiction. Recently, we found trait non-planning impulsiveness measured with the Karolinska Scales of Personality was negatively correlated with dopamine D receptor availability in the ventral striatum of healthy humans. While also observed in rodents, human studies have failed to find this association with other measures of trait impulsivity. We explored whether another rodent finding, reduced ventral striatum volume with greater impulsivity, could also be observed in humans using this scale. Non-planning impulsiveness was measured in 52 healthy subjects (21 female; mean age: 33.06 ± 9.69) using the Karolinska Scales of Personality. Striatal subregion volumes, including the globus pallidus, were acquired using the Multiple Automatically Generated Templates (MAGeT-Brain) algorithm. Although failing to support our a priori hypothesis, there was a significant sex interaction in the post-commissural putamen with impulsiveness. Exploratory analyses revealed impulsiveness was negatively correlated with post-commissural putamen volumes in males, but positively correlated in females. We replicated this finding in males in an increased sample (including all 52 previous subjects) who provided impulsiveness measured by the Temperament and Character Inventory (n = 73; 32 female; mean age: 33.48 ± 9.75). These correlations by sex were statistically different from one another, the main finding with the Kasolinksa Scales of Personality surviving correction for multiple comparisons. While impulsivity may be related to reduced ventral striatal D receptors across sexes, males but not females may show significant reductions in post-commissural putamen volume. These findings have important implications for understanding biological markers underlying sex differences in drug addiction vulnerability.
冲动性被认为是成瘾的易感性特质。最近，我们发现，使用卡罗林斯卡人格量表测量的特质非计划性冲动性与健康人类腹侧纹状体中的多巴胺 D 受体可用性呈负相关。虽然在啮齿动物中也观察到了这种关联，但人类研究未能发现这种关联与其他特质冲动性测量方法有关。我们探讨了另一种啮齿动物发现，即随着冲动性的增加，腹侧纹状体体积减小，是否也可以使用该量表在人类中观察到。使用卡罗林斯卡人格量表在 52 名健康受试者（21 名女性；平均年龄：33.06±9.69）中测量非计划性冲动性。使用多自动生成模板（MAGeT-Brain）算法获取纹状体亚区体积，包括苍白球。尽管未能支持我们的先验假设，但冲动性与后连合壳核之间存在显著的性别交互作用。探索性分析显示，冲动性与男性后连合壳核体积呈负相关，但与女性呈正相关。我们在一个增加的样本中复制了这一发现（包括所有 52 名先前的受试者），他们提供了由气质和性格量表（n=73；32 名女性；平均年龄：33.48±9.75）测量的冲动性。这些按性别分组的相关性彼此存在统计学差异，卡罗林斯卡人格量表的主要发现经多次比较校正后仍然存在。虽然冲动性可能与跨性别降低腹侧纹状体 D 受体有关，但男性而非女性可能会出现后连合壳核体积的显著减少。这些发现对理解药物成瘾易感性性别差异的生物学标志物具有重要意义。
