A neuroimmunological perspective on anxiety disorders.

OBJECTIVE: Research into psychoneuroimmunology has led to substantial advances in our understanding of the reciprocal interactions between the central nervous system and the immune system in neuropsychiatric disorders. To date, the presence of inflammatory responses and the crucial role of cytokines in major depression have been addressed in numerous studies. However, neuroinflammatory hypotheses in anxiety disorders have been studied less extensively than in major depression. There is a high research need for better understanding of both the heterogeneous role of specific cytokines in the control of anxious states and in different anxiety disorders and of the immunomodulating effects of antidepressants on anxiety.
METHODS: Relevant literature was identified through a search of MEDLINE via PubMed. We discuss recent research on neuroimmunology in anxiety and make methodological recommendations for future investigation of neuroinflammatory hypotheses in anxiety disorders.
RESULTS: Some accumulating evidence has indicated modulatory effects of cytokines on neuronal communication and anxiety; however, research has not revealed consistent reproducible findings.
CONCLUSIONS: The availability of inflammatory biomarkers may provide an opportunity to identify patients via specific pathophysiological processes and to monitor therapeutic responses within relevant pathways. Further understanding of the neuroimmunological mechanisms to untangle the reciprocal associations between inflammation and anxiety is warranted.