Article Review By: Kristy Snyder Colling, Ph.D. and Robert Coben, Ph.D.
Article Link: https://www.nature.com/articles/npp2016146
Michopoulos, V., Powers, A., Gillespie, C. F., Ressler, K. J., & Jovanovic, T. (2017). Inflammation in fear-and anxiety-based disorders: PTSD, GAD, and beyond. Neuropsychopharmacology, 42 (1), 254-270.
Anxiety and fear based disorders are among the most common mental health concerns facing Americans today. Disorders such as post-traumatic stress (PTSD), generalized anxiety (GAD), panic (PD), and specific phobias are characterized by exaggerated fear reactions when there is no actual danger and, as such, greatly affect the quality of life for those that suffer with them. The exaggerated fear reactions are not only unsettling while they are being experienced, but they also trigger the immune system to release pro-inflammatory factors into the blood stream. There is mounting evidence that stress-induced inflammation is at the root of many health concerns, including hypertension, cardiovascular risk factors, diabetes, chronic fatigue syndrome, fibromyalgia, gastrointestinal disease, automimmune disorders, arthritis, IBS, and metabolic syndrome. Stress induced inflammation also affects brain structure and function. Indeed, there is evidence that the chronic low-grade inflammation observed in fear and anxiety disorders may lead directlyto alterations in neurobiology critical for control of emotional behavior and fear regulation: In PTSD, GAD, PD, social anxiety, and phobias, there is increased activity in the amygdala in response to threatening stimuli. It is believed that this increased activity is linked to increases in cytokine activity (i.e., inflammation), which has also been linked to greater social disconnection and depressed mood as well as cognitive disturbance and hyperarousal in traumatized individuals with PTSD. Increased inflammation seen in PTSD, GAD, and PD has been shown to affect the structure, function, and connectivity of the hippocampus. Specifically, inflammation may play a role in smaller hippocampal volume and blockage of long-term potentiation, which impairs spatial and contextual memory processing. The dorsal anterior cingulate cortex (dACC) has been found to be the target of a stress response system and cytokine release. This brain region plays a critical role in detecting and responding to threatening social and physical pain stimulus. Indeed, inflammatory processes in dACC may serve as a potent mechanism by which behavioral alterations (i.e., increased attentional bias to threat) may occur in individuals with fear and anxiety disorders. Levels of neurotransmitters are also altered in PTSD and other fear and anxiety related disorders. There is evidence that this may be related to inflammation that specifically reduces GABA concentrations in the insula. As a result, one can see how stress-induced inflammation causes a detrimental cycle where it first affects the brain centers responsible for processing fear and stress and then those areas are in-turn less resilient to stress and trauma. Indeed, those with developmental trauma and those who grow up in low socioeconomic circumstances have been shown to have increased inflammation and are more likely to suffer from PTSD after a traumatic event. This cycle is also behavioral. For example, stress disrupts sleep patterns and severe sleep deprivation affects circulating levels of inflammatory factors. Moreover, PTSD and anxiety disorders are associated with obesity due to emotional eating behavior. And, obesity and high BMI are associated with inflammation markers. The good news is that there are interventions that can be done to arrest or even turn around this cycle and it has to do with nutrition not medication. Indeed, dietary intake and the microbiome are potent modulators of inflammation pathways. It has been suggested that the Mediterranean diet and/or use of probiotics can lead to reduction inflammation. In fact, we at Integrated Health Coaching and as part of our Head On program recommend this as part of our nutrition program. If you would like to learn more about how nutrition can be used to rebalance your brain please contact us and one of our health coaches will be happy to walk with you on your journey to better health.