期刊
JOURNAL OF AFFECTIVE DISORDERS
卷 180, 期 -, 页码 104-111出版社
ELSEVIER
DOI: 10.1016/j.jad.2015.03.035
关键词
Stress; Depression; Anhedonia; Life events; fMRI; Reward processing
资金
- NIMH [R01 MH068376, KOS MH103443]
- NARSAD
- John and Charlene Madison Cassidy Fellowship in Translational Neuroscience through McLean Hospital, a Livingston and a NARSAD Young Investigator award
- Sackler Fellowship in Psychobiology
- NRSA
Introduction: Major depressive disorder (MDD) is often precipitated by life stress and growing evidence suggests that stress induced alterations in reward processing may contribute to such risk. However, no human imaging studies have examined how recent life stress exposure modulates the neural systems that underlie reward processing in depressed and healthy individuals. Methods: In this proof-of-concept study, 12 MDD and 10 psychiatrically healthy individuals were interviewed using the Life Events arid Difficulties Schedule (LEDS) to assess their perceived levels of recent acute and chronic life stress exposure. Additionally, each participant performed a monetary incentive delay task under baseline (no stress) and stress (social evaluative) conditions during functional MRL Results: Across groups, medial prefrontal cortex (mPFC) activation to reward feedback was greater during acute stress versus no-stress conditions in individuals with greater perceived stressor severity. Under acute stress, depressed individuals showed a positive correlation between perceived stressor severity levels and reward-related mPFC activation (r=0.79, p=0.004), whereas no effect was found in healthy controls. Moreover, for depressed (but not healthy) individuals, the correlations between the stress (r=0.79) and no-stress (r=0.48) conditions were significantly different. Finally, reMtive to controls, depressed participants showed significantly reduced mPFC gray matter, but functional findings remained robust while accounting for structural differences. Limitation: Small sample size, which warrants replication. Conclusion: Depressed individuals experiencing greater recent life stress recruited the mPFC more under stress when processing rewards. Our results represent an initial step toward elucidating mechanisms underlying stress sensitization and recurrence in depression. (C) 2015 Elsevier B.V. All rights reserved.
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