Positive affect and health-related neuroendocrine, cardiovascular, and inflammatory processes

Abstract

Negative affective states such as depression are associated with premature mortality and increased risk of coronary heart disease, type 2 diabetes, and disability. It has been suggested that positive affective states are protective, but the pathways through which such effects might be mediated are poorly understood. Here we show that positive affect in middle-aged men and women is associated with reduced neuroendocrine, inflammatory, and cardiovascular activity. Positive affect was assessed by aggregating momentary experience samples of happiness over a working day and was inversely related to cortisol output over the day, independently of age, gender, socioeconomic position, body mass, and smoking. Similar patterns were observed on a leisure day. Happiness was also inversely related to heart rate assessed by using ambulatory monitoring methods over the day. Participants underwent mental stress testing in the laboratory, where plasma fibrinogen stress responses were smaller in happier individuals. These effects were independent of psychological distress, supporting the notion that positive well-being is directly related to health-relevant biological processes.

Fig. 1.

Biological correlates of happiness over the working day. (a) Mean salivary cortisol averaged during the working day in relation to happiness quintile, adjusted for gender, age, grade of employment, BMI, smoking, and psychological distress. Error bars are standard errors of the mean (SEM). Cortisol levels were inversely related to happiness (P = 0.009), and there was no gender difference in this pattern. (b) Mean heart rate averaged during the working day in relation to happiness in men (black bars) and women (hatched bars). Values are adjusted for age, grade of employment, BMI, smoking, and physical activity, and error bars are SEM. The difference across happiness quintiles was significant for men (P = 0.020) but not for women.

Fig. 2.

Happiness and fibrinogen stress responses. Shown is the mean increase in plasma fibrinogen after acute mental stress in the five happiness quintiles, adjusted for gender, age, grade of employment, BMI, smoking, baseline fibrinogen, and GHQ. Error bars are SEM. Differences in fibrinogen stress responses across happiness quintiles were significant (P = 0.011).