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

TitlePerceived life stress exposure modulates reward-related medial prefrontal cortex responses to acute stress in depression.
Publication TypeJournal Article
Year of Publication2015
AuthorsKumar P, Slavich GM, Berghorst LH, Treadway MT, Brooks NH, Dutra SJ, Greve DN, O'Donovan A, Bleil ME, Maninger N, Pizzagalli DA
JournalJ Affect Disord
Date Published2015 Jul 15
KeywordsAdult, Case-Control Studies, Depressive Disorder, Major, Female, Functional Neuroimaging, Gray Matter, Humans, Magnetic Resonance Imaging, Male, Perception, Prefrontal Cortex, Reward, Stress, Psychological, Young Adult

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.

Alternate JournalJ Affect Disord
PubMed ID25898329
PubMed Central IDPMC4451940
Grant ListK08 MH103443 / MH / NIMH NIH HHS / United States
K08MH103443 / MH / NIMH NIH HHS / United States
R00 MH102355 / MH / NIMH NIH HHS / United States
R01 MH068376 / MH / NIMH NIH HHS / United States
R01MH068376 / MH / NIMH NIH HHS / United States