Mood homeostasis: Potential in personalized treatment for depression

Mood homeostasis appears to be impaired in people with low mood and a history of depression, a recent study has shown. These results may provide new insights to guide the development of treatments for depression.

Data for the study were derived from two independent and complementary case-control data sets. The 58sec data set consisted of data of 28,212 young adults (mean age, 28.1 years; female, 65.8 percent) living in high-income francophone countries who self-enrolled into an ecological momentary assessment. The WHO Study on Global Aging and Adult Health (WHO SAGE) data set, formed as part of the WHO SAGE study, consisted of data of 30,116  nationally representative participants (mean age, 57.8 years; female, 57.0 percent) in low- and middle-income countries. [JAMA Psychiatry 2020;e200588]

Mood homeostasis, defined as the stabilization of one’s mood by engaging in mood-modifying activities (eg, exercising), represents the extent to which people demonstrate hedonic flexibility. While it is part of the broader concept of mood regulation, mood homeostasis specifically refers to the moment-to-moment regulation of mood states via choice of activities.

In the 58sec dataset, individuals with low mean mood (ie, mean in the bottom half of the population, 46.9) had significantly lower mood homeostasis than those with high mean mood (ie, mean in the top half of the population, 75.2) (0.63 percent vs 0.96 percent; p<0.001).

Similarly, people with vs without a history of depression had significantly more disrupted mood homeostasis (which may even be effectively absent in some cases) (0.03 vs 0.68 percent; p<0.001) in the WHO SAGE data set. Consistent results were demonstrated when adjusted for the country of origin of individuals.

Engagement in different activities resulted in virtually identical change in mood in all participants, regardless of their mean mood levels (correlation between the horizontal spread of activities within the high mean mood group and that within the low mean mood group, 0.955).

Nonetheless, participants in the two groups differed in their propensity to engage in different activities as a function of their current mood (correlation between the horizontal spread of activities within the high mean mood group and that within the low mean mood group, 0.787).

The difference between two correlations was of statistical significance (difference, 0.17; 95 percent confidence interval [CI], 0.17 to 0.32; p<0.001). People with vs without a history of depression also differed significantly in the same respect (difference, 0.65; 95 percent Cl, 0.41 to 1.03; p<0.001), as shown in the WHO SAGE data set..

In the 58sec data set, mood-decreasing activities (eg, postponing housework) led to a greater between-group difference in mood homeostasis between people with high and low mean mood (difference, 1.27; 95 percent CI, 1.07 to 1.59; p<0.001) vs positive activities (difference, 0.22; 95 percent CI, 0.08 to 0.47; p<0.001), with a statistically significant difference between the two types of activities (1.05; 95 percent CI, 0.81 to 1.41; p<0.001).

In dynamic simulation of mood and activity timelines, individuals with low mood homeostasis were found to be 3 times more likely to have depressive episodes (annual incidence of depressive episodes, 11.8 percent vs 3.8 percent) and a longer depressive duration (4.19 weeks vs 2.90 weeks; p=0.006) than those with high mood homeostasis.

“These mechanistically informed findings may prompt the development of new treatments for depression or the optimization of existing ones, such as activity scheduling,” concluded the researchers.