Why PTSD is a Mind-Body Condition
Post Traumatic Stress Disorder (PTSD) is a mental health condition that affects 10 to 12% of women and five to 6% of men over their lifetimes. A much larger proportion of people have some symptoms of PTSD without the full diagnosis. PTSD occurs in a proportion of people as a result of exposure to trauma and can create a high level of distress and disability. People with PTSD are more likely to suffer from diseases involving systemic inflammation (e.g., cardiovascular disease or diabetes) or to have autoimmune disorders such as asthma. For this reason, experts have argued that PTSD is a mind-body condition involving chronic low level systemic information. People with other mental health disorders (e.g., depression, bipolar disorder) have elevated inflammatory markers in their blood. However, studies of people with PTSD have produced mixed findings. A recent meta-analysis statistically compared the results of all studies in the scientific literature comparing people with PTSD to healthy controls on inflammatory markers.
What is inflammation?
Inflammation is a natural reaction that involves activation of the immune system to fight off viruses and bacteria. However, exposure to chronic stress can cause inflammation in the absence of infection or injury. When inflammation becomes chronic, it can result in autoimmune diseases, premature aging, heart disease, diabetes and a buildup of plaque in the arteries that restricts blood flow (atherosclerosis). Systemic inflammation can be measured by the presence of inflammatory cytokines, chemical messengers that circulate through the bloodstream to activate the immune system to fight off a virus or bacterial pathogen or promote healing.
The authors of the meta-analysis (statistical summary of many research studies) hypothesized that there actually was a relationship between PTSD and elevated inflammatory cytokines. They thought that this relationship was not found in some previous studies because of inconsistencies in whether the participants also had major depressive disorder, the duration of the PTSD, severity of symptoms, whether the participants had another inflammatory disease, medication use, and time of day that the samples were taken. Therefore, they statistically controlled for variability in hese factors and did subgroup analyses (e.g., separately analyzing subjects with or without comorbid depression) to exclude their influence.
Chronic inflammation in PTSD
The authors looked at all studies between 1960 and 2015 that compared inflammatory markers in people with PTSD, compared to healthy controls. Their results showed that concentrations of the inflammatory cytokines interleukin 1 beta, interleukin 6, and interferon were higher in patients with PTSD, compared to healthy controls. When patients with comorbid major depression were excluded, the cytokines interleukin 1 beta, interleukin 6, and TNF alpha were still elevated. Another inflammatory marker, TNF was also increased in patients with PTSD who were medication-free. The longer the duration of PTSD symptoms, the higher the concentration of interleukin 1 beta in medication-free patients. The more severe the symptoms, the higher the concentration of interleukin 6.
Clinical and treatment implications
Clinically, these inflammatory markers can decrease neurogenesis (the process by which new neurons are formed in the brain). This can interfere with the ability of the brain to grow, adapt, and learn from experience. Studies in rats also show that administering interleukin 1 beta can impair memory formation and storage. We know that in PTSD the hippocampus (memory center) has smaller volume and that PTSD memories are stored in a more raw, sensory way than regular memories.
The results of this study show that PTSD is a mind-body disorder, not just a mental health issue. This is consistent with other studies showing that having several adverse childhood experiences (like abuse, parental divorce, poverty etc) is a risk factor for serious physical illnesses, substance abuse, and mental health problems in adulthood. The chronic low level of inflammation that occurs with PTSD does not seem to be the result of an infection or autoimmune disorder. Rather, it seems to be caused by severe psychological stress.
These findings such the need for treatments for PTSD that address inflammation as well as the mental health issues. Aerobic exercise, smoking cessation, and alternative medicine treatments that reduce inflammation are examples of interventions that could supplement regular therapy. Patients also need to learn healthy ways to manage stress, both from internal trauma memories or PTSD symptoms and ongoing life events and relationship struggles. Mindfulness, emotion regulation strategies, or cognitive-behavioral stress-management strategies can supplement treatments that address the trauma directly. If you think you have PTSD, it is important to let your doctor know and consult a mental health professional for evaluation. Untreated PTSD may have serious physical as well as psychological effects.