Researchers have in the past determined that psychological stress is associated with shorter telomere length as measured in immune cells from a blood sample, and greater ill health in general, but there remains considerable uncertainty over the mechanisms involved. There is also a fair degree of research demonstrating associations between personality traits such as conscientiousness and measures of aging. To what degree is this outcome biological versus being based on factors such as failing to take good care of your health? This review of data on posttraumatic stress disorder (PTSD) looks at much the same question:
PTSD is associated with number of psychological maladies, among them chronic depression, anger, insomnia, eating disorders and substance abuse. Now researchers suggest that people with PTSD may also be at risk for accelerated aging or premature senescence. "This is the first study of its type to link PTSD, a psychological disorder with no established genetic basis, which is caused by external, traumatic stress, with long-term, systemic effects on a basic biological process such as aging."
The majority of evidence fell into three categories: biological indicators or biomarkers, such as leukocyte telomere length (LTL), earlier occurrence or higher prevalence of medical conditions associated with advanced age and premature mortality. In their literature review, researchers identified 64 relevant studies; 22 were suitable for calculating overall effect sizes for biomarkers, 10 for mortality. All six studies looking specifically at LTL found reduced telomere length in persons with PTSD.
The scientists also found consistent evidence of increased pro-inflammatory markers, such as C-reactive protein and tumor necrosis factor alpha, associated with PTSD. A majority of reviewed studies found increased medical comorbidity of PTSD with several targeted conditions associated with normal aging, including cardiovascular disease, type 2 diabetes, gastrointestinal ulcer disease and dementia. Seven of 10 studies indicated a mild-to-moderate association of PTSD with earlier mortality, consistent with an early onset or acceleration of aging in PTSD.