Department of PsychiatryGeisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA.
J Am Acad Child Adolesc Psychiatry. 2013 Jul;52(7):747-755.e6. doi: 10.1016/j.jaac.2013.04.013. Epub 2013 Jun 5.
Many adolescents with substance use problems show poor response to evidence-based treatments. Treatment outcome has been associated with individual differences in impulsive decision making as reflected by delay discounting (DD) rates (preference for immediate rewards). Adolescents with higher rates of DD were expected to show greater neural activation in brain regions mediating impulsive/habitual behavioral choices and less activation in regions mediating reflective/executive behavioral choices.
Thirty adolescents being treated for substance abuse completed a DD task optimized to balance choices of immediate versus delayed rewards, and a control condition accounted for activation during magnitude valuation. A group independent component analysis on functional magnetic resonance imaging time courses identified neural networks engaged during DD. Network activity was correlated with individual differences in discounting rate.
Higher discounting rates were associated with diminished engagement of an executive attention control network involving the dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, inferior parietal cortex, cingulate cortex, and precuneus. Higher discounting rates also were associated with less deactivation in a "bottom-up" reward valuation network involving the amygdala, hippocampus, insula, and ventromedial prefrontal cortex. These 2 networks were significantly negatively correlated.
Results support relations between competing executive and reward valuation neural networks and temporal decision making, an important, potentially modifiable risk factor relevant for the prevention and treatment of adolescent substance abuse. Clinical trial registration information-The Neuroeconomics of Behavioral Therapies for Adolescent Substance Abuse, http://clinicaltrials.gov/, NCT01093898.
许多有物质使用问题的青少年对基于证据的治疗反应不佳。治疗结果与冲动决策的个体差异有关，反映在延迟折扣（DD）率上（对即时奖励的偏好）。预计 DD 率较高的青少年在介导冲动/习惯行为选择的大脑区域中表现出更大的神经激活，而在介导反射/执行行为选择的区域中表现出较少的激活。
30 名接受物质滥用治疗的青少年完成了一项 DD 任务，该任务经过优化，可以平衡即时与延迟奖励之间的选择，并控制了在大小评估期间的激活。对功能磁共振成像时间序列进行的组独立成分分析确定了在 DD 期间参与的神经网络。网络活动与折扣率的个体差异相关。
较高的折扣率与执行注意控制网络（涉及背外侧前额叶皮层、背内侧前额叶皮层、下顶叶皮层、扣带回和楔前叶）的参与减少有关。较高的折扣率也与“自上而下”奖励评估网络（涉及杏仁核、海马体、岛叶和腹内侧前额叶皮层）的去激活减少有关。这两个网络呈显著负相关。
结果支持竞争的执行和奖励评估神经网络与时间决策之间的关系，这是一个重要的、潜在可改变的风险因素，与青少年物质滥用的预防和治疗有关。临床试验注册信息-青少年物质滥用行为治疗的神经经济学，http://clinicaltrials.gov/，NCT01093898。
