The association of glutamate level in pregenual anterior cingulate, anhedonia, and emotion-behavior decoupling in patients with major depressive disorder

Abstract

Impairments of translating emotional salience into effortful behavior are core features of anhedonia in cohorts with major depressive disorder. Glutamate metabolism is considered to be involved in this process, but the empirical study is relatively few. Therefore, the present study aimed to examine the correlations between glutamate level in pregenual anterior cingulate, anhedonia, and emotion-behavior decoupling in patients with major depressive disorder. Fifteen individuals diagnosed with major depressive disorder and ten healthy individuals were recruited. All participants were asked to complete self-report instruments for anhedonia and the computerized anticipatory and consummatory pleasure task, and the in vivo glutamate levels were measured by proton magnetic resonance spectroscopy. Thus, a potential lower glutamate levels in pregenual anterior cingulate in individuals with major depressive disorder were founded to be positively correlated with the ability of pleasure experiencing. The mechanism of glutamate in pregenual anterior cingulate in anhedonia in patients with major depressive disorder may be reflected in the early pleasurable experience stage, rather than in the transformation of emotional experience to motivation or reward-seeking behavior, which may be different from that in schizophrenia.

Keywords: Anhedonia; Emotion-behavior decoupling; Glutamate; Magnetic resonance spectroscopy; Major depressive disorder.