Depressive symptom domains exert different effects on proinflammatory cytokines and inhibitory control function among patients with major affective disorders.

Background: Studies have demonstrated the shared and distinct etiologies of different depressive symptom domains. However, less is known about the effects of the three depressive symptom domains, namely the dysphoria, retardation, and vegetative domains, on inhibitory control function and proinflammatory cytokine profiles.

Methods: Our study enrolled 327 adolescent and adult patients with major affective disorders, namely bipolar disorder (n = 94) and major depressive disorder (n = 233). The three-depressive-symptom-domain model of the Montgomery-Åsberg Depression Rating Scale was used in the present study. All participants underwent the go/no-go task and were assessed for the levels of C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α).

Results: Generalized linear models adjusted for age, sex, body mass index, and education years indicated that the dysphoria domain was positively associated with the levels of CRP (B = 0.034, p = 0.022) and TNF-α (B = 0.007, p = 0.020) and with errors in the go/no-go task (B = 0.155, p < 0.001). Additionally, in the go/no-go task, the retardation domain was positively correlated with response time (B = 5.418, p = 0.019), whereas the vegetative domain was negatively correlated with correct responses (B = -0.131, p = 0.015).

Discussion: Our findings suggest that different symptom domains of depression exert different effects on proinflammatory cytokine profiles and inhibitory control function, which may reflect the heterogeneity of depressive episodes.