Cardiovascular Stress Biomarkers and Mental-Health Risk

Source: Pexels.com_Anna Shvets

While being stuck in traffic is definitely irksome, when you are stuck in traffic and late for work it is likely to be more stressful. Each of us can think of instances in our everyday lives when such mundane but irksome, annoying, disrupting events cause emotional reactions making us angry or frustrated and causing us some degree of stress. On the face of it, these are relatively minor stressors and acute in duration — i.e, they don’t last very long, and our emotional reactions will dissipate shortly afterward. However, even though they may appear harmless, for some people these relatively mundane acute stressors can become toxic for their health. For example, the cardiovascular reactivity hypothesis is a well-established paradigm in the psychophysiology, with robust evidence linking atypical cardiovascular reactions, which include both exaggerated and blunted blood-pressure responses to acute stressors, to a heightened risk of hypertension, as well as cardiovascular disease. In this type of reactivity research, healthy participants have their blood pressure and heart-rate responses monitored throughout a resting baseline while they undergo an acute stressor, such as public speaking task, or a maths task. The level of cardiovascular changes from baseline to task is the index used to investigate its predictive utility in conferring risk for future health outcomes. I have previously written about how these atypical responses to acute stressors are relatively stable across stressors, and subject to individual differences and their impact on cardiovascular health.

More recently, a new body of research has found that consequences of atypical reactions extend beyond physical health with consequences for mental health. One study in particular, led by researchers at Baylor University, has found that blunted cardiovascular reactivity was predictive of behavioral disengagement, a coping style linked to motivational dysregulation and risk of depression. In this study, 452 healthy people participated in an acute stress testing protocol in which their blood pressure and heart rates were monitored throughout a resting baseline and a stressor period. The authors found that lower levels of cardiovascular heart reactivity were associated with behavioral disengagement. Importantly, this result was still evident even after they controlled for several potential confounding factors including, age, gender, race, ethnicity, socioeconomic status, depressive symptomology, self-report stress task stressfulness, and self-report stress task demandingness, making the finding more robust.

What does this all mean?

Source: Pexels_Inzmam Khan

It suggests that atypical cardiovascular reactions and heart disease association extends beyond physical health to mental health. Recent theories on the neuroscience of depression have identified motivational dysregulation and disengagement with emotionally negative material as a risk factor for depression. Thus, if these factors are implicated in risk of depression, and cardiovascular reactivity are predictive of these behavioral patterns, then by extension it would imply that blunted cardiovascular reactivity may have utility in the area of predicting risk of depression. In fact, some evidence to support this notion has already emerged, and perhaps given that atypical cardiovascular reactivity is heritable, stable, and subject to individual differences it maybe an early biomarker of depression risk.