Dillon Daniel G, Holmes Avram J, Birk Jeffrey L, Brooks Nancy, Lyons-Ruth Karlen, Pizzagalli Diego A
Department of Psychology, Harvard University, Cambridge, Massachusetts 02138, USA.
Biol Psychiatry. 2009 Aug 1;66(3):206-13. doi: 10.1016/j.biopsych.2009.02.019. Epub 2009 Apr 9.
Childhood adversity increases the risk of psychopathology, but the neurobiological mechanisms underlying this vulnerability are not well-understood. In animal models, early adversity is associated with dysfunction in basal ganglia regions involved in reward processing, but this relationship has not been established in humans.
Functional magnetic resonance imaging was used to examine basal ganglia responses to: 1) cues signaling possible monetary rewards and losses; and 2) delivery of monetary gains and penalties, in 13 young adults who experienced maltreatment before age 14 years and 31 nonmaltreated control subjects.
Relative to control subjects, individuals exposed to childhood adversity reported elevated symptoms of anhedonia and depression, rated reward cues less positively, and displayed a weaker response to reward cues in the left globus pallidus. There were no group differences in right hemisphere basal ganglia response to reward cues or in basal ganglia response to loss cues, no-incentive cues, gains, or penalties.
Results indicate that childhood adversity in humans is associated with blunted subjective responses to reward-predicting cues as well as dysfunction in left basal ganglia regions implicated in reward-related learning and motivation. This dysfunction might serve as a diathesis that contributes to the multiple negative outcomes and psychopathologies associated with childhood adversity. The findings suggest that interventions that target motivation and goal-directed action might be useful for reducing the negative consequences of childhood adversity.
童年期逆境会增加精神病理学风险,但这种易感性背后的神经生物学机制尚未完全明了。在动物模型中,早期逆境与参与奖赏加工的基底神经节区域功能障碍有关,但这种关系在人类中尚未得到证实。
使用功能磁共振成像来检查13名在14岁之前遭受过虐待的年轻成年人和31名未受虐待的对照受试者的基底神经节对以下情况的反应:1)预示可能的金钱奖励和损失的线索;2)金钱收益和惩罚的发放。
与对照受试者相比,暴露于童年期逆境的个体报告快感缺乏和抑郁症状加剧,对奖励线索的评价不那么积极,并且在左侧苍白球对奖励线索的反应较弱。在右半球基底神经节对奖励线索的反应或基底神经节对损失线索、无激励线索、收益或惩罚的反应方面,两组之间没有差异。
结果表明,人类童年期逆境与对奖励预测线索的主观反应迟钝以及与奖励相关学习和动机有关的左侧基底神经节区域功能障碍有关。这种功能障碍可能是一种素质,导致与童年期逆境相关的多种负面结果和精神病理学。研究结果表明,针对动机和目标导向行动的干预措施可能有助于减少童年期逆境的负面影响。