Table 1.
Summary of studies published in the literature showing changes in the activation of different regions
| Study | Experimental groups | Experimental treatment | Effects |
|---|---|---|---|
| Epstein et al83 | Healthy controls and MDD patients | Presentation of positive and negative words | • Diminished activation of ventral striatum in response to positive stimuli • Diminished activation of DMPFC in response to positive stimuli |
| Admon et al133 | Healthy controls and MDD patients | Monetary incentive delay task | • Decreased caudate–dACC connectivity in response to reward |
| Gabbay et al90 | Healthy controls (adolescents) and MDD patients | N/A | • Increased striatum–DMPFC and ventral caudate–ACC connectivity • ACC, supplementary motor area, and supramarginal gyrus connectivity associated with anhedonia severity |
| Heller et al91 | Healthy controls and MDD patients | Emotion regulation task | • MDD patients were unable to sustain the activity in the NA in response to positive emotions • MDD patients have reduced PFC activity |
| Mitterschiffthaler et al85 | Healthy controls and MDD patients with anhedonia | Presentation of positive images | • Decreased activation in the medial frontal cortex • Increased activation in the inferior frontal cortex, ACC, thalamus, putamen, and insula in response to positive stimuli |
| Light et al86 | Healthy controls, MDD patients, and MDD patients treated with venlafaxine-ER or fluoxetine | Emotion regulation task | • MDD patients had a diminished ability to inhibit the reduction in the VLPFC activity during suppression of positive emotions • Lowest VLPFC activity during suppression of positive emotions correlated with greatest reduction in anhedonia due to treatment |
| Harvey et al51 | Healthy controls with various degrees of anhedonia | Presentation of positive stimuli | • Anhedonia inversely related to anterior caudate volume • Positively related to VMPFC activity |
| Keller et al84 | Healthy controls with various degrees of anhedonia | Presentation of musical stimuli | • Anhedonia negatively correlated with activation of NA, basal forebrain, hypothalamus, anterior insula, and orbitofrontal cortex • Anhedonia negatively correlated with the connectivity between NA, VTA, and paralimbic areas |
| Pizzagalli et al89 | Healthy controls and MDD patients with anhedonia | Monetary incentive delay task | • MDD patients had weaker responses to monetary gains in the NA and the caudate • Severity of anhedonia and MDD associated with a reduced caudate volume |
| Wacker et al87 | Healthy controls with anhedonia | Monetary incentive delay task | • Anhedonia correlated with reduced NA activation in response to reward • Anhedonia correlated with reduced NA volume, increased resting activity in the rostral ACC |
| Keedwell et al11 | MDD patients with varying degrees of anhedonia | Presentation of happy and sad emotional stimuli | • Anhedonia positively correlated with VMPFC activity • Anhedonia negatively correlated with amygdala and ventral striatum activity |
Abbreviations: MDD, major depressive disorder; DMPFC, dorsomedial prefrontal cortex; dACC, dorsal anterior cingulate cortex; N/A, not applicable; ACC, anterior cingulate cortex; NA, nucleus accumbens; ER, extended release; VLPFC, ventrolateral prefrontal cortex; VMPFC, ventromedial prefrontal cortex; VTA, ventral tegmental area.