Posttraumatic stress disorder (PTSD) develops after exposure to a traumatic event, which can involve witnessing the traumatic event or directly experiencing the trauma. 1 The prevalence of PTSD in the general population is approximately 7% to 8%. 1 However, not everyone who experiences trauma develops PTSD since the majority of men and women experience at least 1 traumatic event in their lifetimes but do not develop PTSD. 1
In order to be diagnosed with PTSD, a patient must meet several criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). 2 The patient is required to have exposure to trauma, begin having a certain number of prespecified symptoms, and these symptoms must persist for at least a month. 2 Symptoms of PTSD include re-experiencing the traumatic event, avoidance of stimuli associated with the trauma, negative cognitions and mood, and hyperarousal. 3,4 The hyperarousal that is associated with PTSD has been theorized to be either a result of the trauma experienced or exacerbation of a pre-existing tendency. 5 This can manifest in various ways, such as hypervigilance, exaggerated startle response, trouble sleeping, problems concentrating, or irritability. 3,5 These symptoms can cause individuals with PTSD to have elevated levels of stress and to experience difficulties with completing everyday tasks. 6
PTSD and Inflimmation-Related Medical Conditions
Posttraumatic stress disorder has been linked to various physical health problems. Studies have found that PTSD is often comorbid with cardiovascular, autoimmune, musculoskeletal, digestive, chronic pain and respiratory disorders. 3,7-11 Inflammation may be a contributing factor in the associations between PTSD and these conditions. 12-16 Studies have found that increases in pro-inflammatory cytokines and interferons are associated with PTSD, as well as changes in immune-related blood cells. 12-16
Considering that PTSD has been linked to many medical conditions that have inflammatory components, especially cardiovascular disease, inflammatory markers may be early indicators of PTSD. 12-16 Additionally, inflammatory markers such as cytokines and interferons can be targeted through medications, and potentially influence symptoms. 13 However, the relation between PTSD and inflammation remains unclear. Associations between PTSD and inflammation-related medical conditions may be due to confounding variables, such as sociodemographic characteristics and health behaviors. Moreover, the list of inflammation-related medical conditions is long and there is no universal agreement of what conditions are related to inflammation.
We recently conducted an epidemiological study using a representative sample of residents living in New York City and found significant associations between PTSD and some inflammation-related medical conditions. 8 We found that participants who had PTSD were more than 4 times more likely to report having had a heart attack or emphysema than were those without PTSD. In addition, participants with PTSD were 2 times more likely to report having hypercholesterolemia, insulin resistance, and angina than were those without PTSD. However, we also found that participants who had PTSD were less likely to develop other inflammation-related conditions like hypertension, type 1 diabetes mellitus, asthma, coronary heart disease, stroke, osteoporosis, and failing kidney.
Together, these associations suggest there is a strong link between PTSD and certain medical conditions, but the link may not be solely based on inflammation. 8 Moreover, positive associations between PTSD and hypertension, asthma, and coronary heart disease disappeared when depression was controlled for. This finding points to depression as a major factor, consistent with previous findings that depression is associated with the development of various medical conditions and may be a stronger factor than PTSD. 8