Department of Psychology, Stanford University, Stanford, CA 94305, USA.
J Abnorm Psychol. 2012 Feb;121(1):51-60. doi: 10.1037/a0024945. Epub 2011 Aug 15.
Anhedonia, the lack of interest or pleasure in response to hedonic stimuli or experiences, is a cardinal symptom of depression. This deficit in hedonic processing has been posited to influence depressed individuals' motivation to engage in potentially rewarding experiences. Accumulating evidence indicates that hedonic processing is not a unitary construct but rather consists of an anticipatory and a consummatory phase. We examined how these components of hedonic processing influence motivation to obtain reward in participants diagnosed with major depression and in never-disordered controls. Thirty-eight currently depressed and 30 never-disordered control participants rated their liking of humorous and nonhumorous cartoons and then made a series of choices between viewing a cartoon from either group. Each choice was associated with a specified amount of effort participants would have to exert before viewing the chosen cartoon. Although depressed and control participants did not differ in their consummatory liking of the rewards, levels of reward liking predicted motivation to expend effort for the rewards only in the control participants; in the depressed participants, liking and motivation were dissociated. In the depressed group, levels of anticipatory anhedonia predicted motivation to exert effort for the rewards. These findings support the formulation that anhedonia is not a unitary construct and suggest that, for depressed individuals, deficits in motivation for reward are driven primarily by low anticipatory pleasure and not by decreased consummatory liking.
快感缺失,即对愉悦刺激或体验缺乏兴趣或愉悦感,是抑郁症的一个主要症状。这种愉悦处理的缺陷被认为会影响抑郁个体参与潜在奖励体验的动机。越来越多的证据表明,愉悦处理不是一个单一的结构,而是由预期和满足两个阶段组成。我们研究了这些愉悦处理成分如何影响患有重度抑郁症的参与者和从未失调的对照组获得奖励的动机。38 名当前抑郁和 30 名从未失调的对照组参与者对幽默和非幽默卡通的喜爱程度进行了评分,然后在两组中的一组卡通之间进行了一系列选择。每个选择都与参与者在观看所选卡通片之前必须付出的特定努力量相关联。尽管抑郁和对照组参与者在对奖励的满足性喜爱方面没有差异,但奖励喜爱程度仅在对照组参与者中预测了为奖励付出努力的动机;在抑郁组中,喜爱和动机是分离的。在抑郁组中,预期快感缺失的程度预测了为获得奖励而付出努力的动机。这些发现支持了快感缺失不是一个单一结构的观点,并表明对于抑郁个体来说,奖励动机的缺陷主要是由低预期愉悦驱动的,而不是由满足性喜爱降低驱动的。