Background: Stress, one of the strongest risk factors for depression, has been linked to "anhedonic" behavior and dysfunctional reward-related neural circuitry in preclinical models.
Methods: To test if acute stress reduces reward responsiveness (i.e., the ability to modulate behavior as a function of past reward), a signal-detection task coupled with a differential reinforcement schedule was utilized. Eighty female participants completed the task under both a stress condition, either threat-of-shock (n = 38) or negative performance feedback (n = 42), and a no-stress condition.
Results: Stress increased negative affect and anxiety. As hypothesized based on preclinical findings, stress, particularly the threat-of-shock condition, impaired reward responsiveness. Regression analyses indicate that self-report measures of anhedonia predicted stress-induced hedonic deficits even after controlling for anxiety symptoms.
Conclusions: These findings indicate that acute stress reduces reward responsiveness, particularly in individuals with anhedonic symptoms. Stress-induced hedonic deficit is a promising candidate mechanism linking stressful experiences to depression.