Exposure to Violence, Psychosocial Stress, and Asthma.

Over the last two decades, chronic psychosocial stress has been linked to asthma. Exposure to violence is a common stressor for people living in urban settings, particularly in the U.S, and has received increased attention in the asthma literature in recent years. Improving our understanding of whether and how exposure to chronic stressors causes or worsens asthma could help us gain insights into disease pathogenesis, design public health policies, and develop new therapies. In this review, we assess the evidence linking violence or stress to asthma, describe recent insights on potential mechanisms, and discuss challenges and future directions. To date, experimental and observational studies suggest a causal association between chronic stress and worse asthma control, and a growing body of literature suggests that pre- or post-natal chronic stress may lead to new-onset asthma. Such evidence supports conducting randomized controlled trials of stress-reduction interventions to improve asthma control in subjects with high chronic stress. On the other hand, additional studies are needed to better understand if the specific stressor of violence exposure leads to asthma or worse asthma outcomes. Longitudinal studies with assessment of co-exposures and coping mechanisms are key to not only better understand the independent effects of violence or stress on asthma but also to identify factors that could ameliorate or worsen such effects. At this time, preliminary evidence supports prospective studies of whether and how chronic stress affects asthma or treatment responses through changes in DNA methylation or gene expression in cells relevant to disease pathogenesis.