Inflammation and the dimensions of depression: A review

• Published in: Frontiers in neuroendocrinology Vol. 56; p. 100800
• Main Authors: Majd, Marzieh, Saunders, Erika F.H., Engeland, Christopher G.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2020
• Subjects: Adolescent; Adult; Affect; Aged; Anhedonia; Appetite; Biomarkers - blood; C-reactive protein; C-Reactive Protein - analysis; Cognition - physiology; Cognitive symptom; Cytokine; Cytokines - blood; Depression - physiopathology; Depression - psychology; Depressive symptom; Fatigue; Female; Humans; Inflammation - psychology; Male; Middle Aged; Mood; Neurovegetative symptom; Somatic symptom; Depressive symptom; Mood; C-reactive protein; Cytokine; Somatic symptom; Anhedonia; Fatigue; Neurovegetative symptom; Cognitive symptom
• ISSN: 0091-3022; 1095-6808
• DOI: 10.1016/j.yfrne.2019.100800

•There might be a unique association between neurovegetative symptoms and inflammation.•Cognitive symptoms were not associated with inflammation independent of neurovegetative symptoms.•Higher baseline neurovegetative symptoms predicted increases in inflammation over time.•Higher baseline inflammation predicted mood and cognitive symptoms over time. Patients with depressive disorders show a wide range of clinical manifestations including cognitive and neurovegetative symptoms. Importantly, these symptoms can differ in terms of biological etiology, and deconstructing depression into specific symptoms may provide valuable insight into the underlying neurobiology. Little research has examined inflammation in the context of depressive dimensions. Here we conduct a narrative review of the existing literature (21 studies) to elucidate whether the depression-inflammation link is symptom specific. Overall, there is evidence that an association exists between neurovegetative symptoms of depression and inflammation, independent of cognitive symptoms. The same cannot be said of cognitive symptoms and inflammation. There is also some evidence of gender differences in the directionality of the relationship between depression and inflammation. Potential explanations for these findings, limitations of the existing literature and recommendations for future research design are discussed.