The Science of Stress

Individual stress reactivity

A variety of individual-level factors affect stress activity.

For instance, depression worsens stress reactivity; however, the opposite also occurs: Greater stress reactivity increases inflammation and worsens depression.

Even a history of depression is linked with greater stress reactivity. Why?

The scar theory of depression suggests major depressive episodes (e.g. in reaction to the loss of a parent) leave behind “scars.” These scars sensitize the individual and increase the likelihood that comparably minor events (e.g. changing schools) will trigger episodes of depression.

Mood disorders may, when combined with heightened (提高) stress response, influence other aspects of well-being as well. For instance, they can result in weight gain. Kiecolt-Glaser found that adults with a history of mood disorders who were more hostile (敌对的，怀有敌意的) during marital (夫妇的) conflict discussions as well had decreased postmeal resting energy expenditure (静息时能量消耗)—equivalent to a weight gain of nearly eight pounds (if sustained for a year).

Other individual-level influences on stress include cognitive factors: Rumination (沉思), worry, and anticipatory (预期的，提早发生的) anxiety. These often prolong or worsen physiological arousal, meaning they result in higher blood pressure and cortisol (皮质醇) levels, and worse HRV reactions.

Last, in terms of (就…而言，依据，按照) the effects of early life adversity (逆境，不幸), the Biological Embedding Model suggests stressful experiences like childhood abuse and trauma are “programmed” into immune cells involved in the inflammatory response, making them more reactive to stress. Therefore, individuals who have experienced childhood abuse might have greater stress reactivity even many years after the maltreatment (虐待) ended.

Interpersonal stress reactivity

People also influence the stress reactivity of others, such as their romantic partners. How?

During interactions, romantic partners’ stress levels may synchronize (同步，合拍), and, over time, partners could begin to respond in a more similar way to the same stressors.

Of course, couples can influence each other positively too. Positive relationships are characterized by mutual validation and support (互相认可和支持), which help reduce stress reactivity. In contrast, negative relationships are characterized by frequent conflict and hostility (敌意，敌对) (e.g., eye-rolling, sarcasm (讽刺，嘲笑)). And, as it occurs in some unhappy marriages, sometimes romantic partners become stuck in a negative cycle of violence and abuse, which results in increased stress reactivity and a greater chance of developing a mental illness.

Research by the authors of the current review found that compared with less hostile (敌对的) pairs, newlyweds (新婚夫妇) who expressed more hostility during marital discussions showed higher levels of stress hormones such as epinephrine (肾上腺素). More importantly, “Postconflict epinephrine in the first year of marriage was 34% higher in couples who subsequently divorced than [ones] still married 10 years later.”

Techniques for managing stress reactivity

In summary, greater stress reactivity results in physiological dysregulation, which is associated with chronic diseases like heart disease, autoimmune disorders, and clinical depression. These conditions often have a negative effect on stress reactivity. This results in a vicious cycle (恶性循环) that worsens systemic inflammation, immune functioning, and chronic diseases, and contributes to frailty, accelerated aging, and possibly early mortality. See Figure 1.

Arash Emamzadeh (adapted from Kiecolt-Glaser et al., 2020)

What can we do to break this vicious cycle?

Managing stress reactivity requires learning about factors that influence the stress response, and then identifying and altering modifiable influences on stress, such as unhealthy thinking patterns (e.g., rumination, worry) and dysfunctional communication patterns (e.g., sarcasm, insults).

As for reducing stress reactivity more directly, one possibility is to stimulate the parasympathetic (副交感神经) nervous system (e.g., using breathing techniques) to counterbalance (使平衡，自动抵消) the effect of the sympathetic (交感神经) nervous system.

Popular stress management techniques—contemplative (沉思，冥想的) practices such as yoga and mindfulness meditation (正念冥想)—may also reduce stress reactivity.

For instance, in one investigation, experienced yoga practitioners had lower levels of IL-6 (an inflammatory marker) when compared to yoga practitioners with less experience. And a meta-analysis concluded (推断) meditation is associated with reduced markers of stress—reduced cortisol, blood pressure, and C-reactive protein (an inflammatory marker).

Last, as the authors note, aside (除了) from meditation, “exercise, a healthy diet low in sugar and saturated fats (饱和脂肪酸), and regular high-quality sleep may also reduce stress reactivity as well as depressive symptoms.”

vicious cycle ： 恶性循环

in terms of ：就…而言，依据，按照

See you tomorrow