High levels of TNF-α are associated with symptoms of depression in health professionals at a hospital

Abstract

Objective: The current evidence indicates that inflammation is highly related to depression but not to anxiety in clinical samples. However, less understood is the relationship between inflammation and symptoms of depression and anxiety in a nonclinical sample. The aim of this study was to investigate the association between three inflammation markers and symptoms of depression and anxiety in a healthy sample without a history of psychiatric disorders.

Methods: Symptoms of depression and anxiety were evaluated in 74 healthy adults (mean age=42.3; SD=11.8) using the Hospital Anxiety and Depression Scale. We assessed proinflammatory cytokines (TNF-α, IL-1β, and CRP), and morning cortisol levels using blood samples.

Results: TNF-α correlates positively with depressive symptoms, but there were no significant relationships between anxiety scores and inflammation markers. Importantly, TNF-α relates to symptoms of depression independently of anxiety scores, age, body mass index, cortisol, and sex.

Conclusions: Our results indicate that TNF-α is associated with depressive symptoms, independently of anxiety, age, body mass index, cortisol, and sex, even in a sample of hospital health professionals without diagnosis or psychiatric history.

Keywords: Affective state; Negative emotions; Proinflammatory cytokines; Psychoneuroimmunology; TNF-α.