More and more evidences have related anxiety and depression to elevated systemic inflammation (Duivis et al., 2013). As complex disorders, anxiety and depression have heterogeneity in symptoms with both physical and cognitive aspects.
What are the roles of inflammation in the cognitive and somatic aspects of anxiety disorders?
A study done in Netherlands analyzed the possible differences in the connections between inflammation with the cognitive and somatic symptoms of anxiety disorders among 2861 subjects (Duivis et al., 2013). The researchers measured the blood samples about the inflammatory biomarkers including C-Reactive Protein (CRP), interleukin (IL)-6, and Tumor Necrosis Factor (TNF)-α.
The study found that the somatic symptoms in depression were significantly related to elevated concentrations of CRP, IL-6 and TNF-α (Duivis et al., 2013). In addition, the somatic symptoms in anxiety were also related to increased concentrations of CRP, IL-6 and TNF-α. Furthermore, the cognitive symptoms in anxiety were related to CRP among male subjects. The unhealthy lifestyle was suggested to provide the connections.
The study indicate that the somatic symptoms of anxiety disorders may have significant connections with inflammation (Duivis et al., 2013). Unhealthy lifestyles may have a role in such connections. More studies in psychoneuroimmunology (PNI) are still needed to understand the pathways in such connections with more detailed explanations of the roles of inflammation in cognitive symptoms.
Duivis HE, Vogelzangs N, Kupper N, de Jonge P, Penninx BW. Differential association of somatic and cognitive symptoms of depression and anxiety with inflammation: findings from the Netherlands Study of Depression and Anxiety (NESDA). Psychoneuroendocrinology. 2013 Sep;38(9):1573-85. doi: 10.1016/j.psyneuen.2013.01.002.