Wacker Jan, Dillon Daniel G, Pizzagalli Diego A
Department of Psychology, Philipps-Universitaet, Marburg, Germany.
Neuroimage. 2009 May 15;46(1):327-37. doi: 10.1016/j.neuroimage.2009.01.058. Epub 2009 Feb 6.
Anhedonia, the reduced propensity to experience pleasure, is a promising endophenotype and vulnerability factor for several psychiatric disorders, including depression and schizophrenia. In the present study, we used resting electroencephalography, functional magnetic resonance imaging, and volumetric analyses to probe putative associations between anhedonia and individual differences in key nodes of the brain's reward system in a non-clinical sample. We found that anhedonia, but not other symptoms of depression or anxiety, was correlated with reduced nucleus accumbens (NAcc) responses to rewards (gains in a monetary incentive delay task), reduced NAcc volume, and increased resting delta current density (i.e., decreased resting activity) in the rostral anterior cingulate cortex (rACC), an area previously implicated in positive subjective experience. In addition, NAcc reward responses were inversely associated with rACC resting delta activity, supporting the hypothesis that delta might be lawfully related to activity within the brain's reward circuit. Taken together, these results help elucidate the neural basis of anhedonia and strengthen the argument for anhedonia as an endophenotype for depression.
快感缺失，即体验愉悦的倾向降低，是包括抑郁症和精神分裂症在内的几种精神疾病的一个有前景的内表型和易感性因素。在本研究中，我们使用静息脑电图、功能磁共振成像和容积分析，来探究在非临床样本中快感缺失与大脑奖赏系统关键节点的个体差异之间的假定关联。我们发现，快感缺失而非抑郁或焦虑的其他症状，与伏隔核对奖赏（金钱激励延迟任务中的收益）的反应降低、伏隔核体积减小以及前额叶前扣带回皮质（rACC）静息δ电流密度增加（即静息活动减少）相关，该区域先前与积极的主观体验有关。此外，伏隔核奖赏反应与rACC静息δ活动呈负相关，支持了δ可能与大脑奖赏回路内的活动有规律关联的假说。综上所述，这些结果有助于阐明快感缺失的神经基础，并加强了将快感缺失作为抑郁症内表型的论据。
