Associations between daily outdoor temperature and subjective real-time ratings of emotional states and sleep in mood disorder subtypes.

There is growing evidence for the influence of weather on mental health at both the aggregate level indices of mental health statistics of hospitalizations, morbidity, and mortality, and individual level dynamics of mood states. Most research on this topic has focused on light exposure and depressed mood as the sole indicators of seasonal fluctuations of mood disorders. This paper evaluates the association between daily maximum outdoor temperature (DMOT) and contemporaneously reported mood, energy, anxiousness, and sleep quality assessed with Ecological Momentary Assessment (EMA) in a community-based sample of 452 people, aged 11 to 85 years, comprising people with or without a history of mood disorders. After controlling for demographics, daily activity levels, and daytime cloud coverage as an index of light exposure, we found that higher DMOT was associated with better mood, increased energy, and better sleep quality among those with a history of mood disorders, particularly in the spring. These findings suggest that the dynamics of mood, energy, and sleep may underlie the aggregate population-level influences of temperature and correlated environmental influences on negative mental health outcomes, particularly among those with BD. Therefore, the conceptualization of risk and intervention for mood disorders should consider both the aggregate influences of temperature and light and associated environmental conditions, as well as individual-level sleep quality and energy as potential mechanisms for seasonal patterns of emotional states.