Table 1.
Overview of studies evaluating reward processing in MDD using fMRI and functional connectivity analysis.
| Authors | Year | n (total) | n (patients) | n (HC) | Task/Stimulus | ROI/Seeds | Observed Effects (HCs vs MDDs) Decreased (↓)/ Increased (↑) Functional Connectivity or Activiton in fMRI |
|---|---|---|---|---|---|---|---|
| Johnston | 2015 | 40 | 20 MDD | 20 | Modified Pessiglione task | Dorsal raphe nuclei | ↑: Significant hippocampal overactivity during loss events in MDD compared to HC |
| Cheng | 2016 | 909 | 421 MDD | 488 | None | Voxel-level BWAS |
↓: Altered functional connectivity in MDD in circuit involving the medial OFC (BA 13), the parahippocampal gyrus, and medial temporal lobe (perirhinal cortex BA 36 and entorhinal cortex BA 28) |
| Dombrovski | 2015 | 78 | 47 MDD | 31 | Probabilistic learning | Striatum, left operculoinsular cortex, right vlPFC, bilateral STG, bilateral thalamus, PCC | ↓: Disrupted differential connectivity between striatum and operculo insular cortex in response to unpredicted rewards vs. unpredicted punishments in MD |
| Gong | 2017 | 123 | 80 MDD | 43 | None | NAc | ↓: Decreased FUCO between NAc and caudate, mid OFC and mOFC, rACC, insular lobe, superior temporal gyrus |
| Greenberg | 2015 | 148 | 148 MDD | 0 | Monetary reward | VS | ↓: Greater anhedonia severity was associated with a reduced reward expectancy-prediction error inverse relationship in the VS |
| Pizzagalli | 2009 | 61 | 30 MDD | 31 | Monetary incentive delay | - | ↓: MDD participants showed significantly weaker responses to gain in the left NAc and bilateral caudate |
| Robinson | 2012 | 27 | 13 MDD | 14 | Mixed reward and punishment learning | Bilateral caudate and putamen | ↓: Impaired reward (but not punishment) reversal accuracy was found alongside attenuated anteroventral striatal response to unexpected reward in MDD |
| Young | 2016 | 43 | 21 MDD | 22 | Pleasant/unpleasant sound stimuli | pVMPFC | ↓: Negative correlation between anhedonia and FUCO between pVMPFC and NAc, left VTA/SN, left OFC and right mid- insula and pVMPFC to middle temporal gyrus/superior temporal sulcus, right inferior frontal gyrus pars opercularis |
All studies investigating reward processing in depression in MDD vs healthy volunteers are included, if functional connectivity was also analyzed these results are also specified.
Abbreviations: BA, Broca area; BWAS, brain-wide association study; FUCO, functional connectivity; HC, healthy controls; MDD, major depressive disorder; mOFC, medial orbitofrontal cortex; midOFC, middle orbitofrontal cortex; NAc, Ncl. accumbens (ventral striatum); OFC, orbitofrontal cortex; PCC, posterior cingulate cortex; pVMPFC, posterior ventromedial prefrontal cortex; rACC, rostral ACC; STG, superior temporal gyrus; vlPFC, ventrolateral prefrontal cortex; VS, ventral striatum; VTA, ventral tegmental area.