Table 1.

Reward system deficits implicated in anhedonia

Deficit	MDD	SZ	Research
Motivation	Diminished	Diminished	Sherdell et al26
			Treadway et al118
			Fervaha et al59
Attention allocation	Not evaluated	Toward nonreward cues	McCarthy et al38
			Barch et al39
Anticipatory pleasure	Diminished	Diminished	Gard et al48
			Sherdell et al26
			Chase et al119
			Arrondo et al120
			Loas et al49
			Liu et al37
Reward learning and integration	Diminished	Diminished pleasure recall	Marder and Galderesi30
			Steele et al121
			Kumar et al122
			Strauss et al117
			Waltz et al44, 56 Gold et al57
			Pizzagalli et al83 Vrieze et al36
Prediction error	Reduced signaling in NAc, caudate, and midbrain	Reduced signaling in hippocampal areas	Gradin et al95
Consummatory pleasure	Mildly diminished	Maintained	Sherdell et al26
			Strauss and Gold34
			Treadway and Zald16
			Da Silva et al53

MDD, major depressive disorder; SZ, schizophrenia.