Perceived life stress exposure modulates reward-related medial prefrontal cortex responses to acute stress in depression

Poornima Kumar*, George M. Slavich, Lisa H. Berghorst, Michael T. Treadway, Nancy H. Brooks, Sunny J. Dutra, Douglas N. Greve, Aoife O'Donovan, Maria E. Bleil, Nicole Maninger, Diego A. Pizzagalli

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

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 and 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 MRI. 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, relative 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.

Original languageEnglish (US)
Pages (from-to)104-111
Number of pages8
JournalJournal of Affective Disorders
Volume180
DOIs
StatePublished - Jul 15 2015

Keywords

  • Anhedonia
  • Life events
  • Reward processing
  • Stress Depression
  • fMRI

ASJC Scopus subject areas

  • Clinical Psychology
  • Psychiatry and Mental health

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