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Less daylight may lead to poorer mental health

Fewer daylight hours between sunrise and sunset was associated with poorer mental health, according to recent findings.

“There is a common perception that weather can play a critical part in the way a person feels at a given moment. Common metaphors such as ‘under the weather’ reflect evidence of the pervasiveness of this belief. The belief that weather influences mood has also resulted in multiple research hypotheses, which have been well-researched with varied results,” Mark E. Beecher, PhD, of Brigham Young University, and colleagues wrote.

To assess associations between weather, pollution and mental health, researchers studied 19 weather and pollution variables with self-reported mental health data for university students participating in mental health treatment (n = 16, 452).

Analysis indicated seasonal changes in sun time best accounted for associations between weather variables and mental health distress.

Fewer sun time hours were associated with increased mental health distress.

A separate analysis of participants’ self-reported suicidality indicated a similar pattern, though it was not significant.

Pollution was associated with changes in mental health distress, but this was mediated by sun time, according to researchers.

“On a rainy day, or a more polluted day, people assume that they’d have more distress. But we didn’t see that. We looked at solar irradiance, or the amount of sunlight that actually hits the ground. We tried to take into account cloudy days, rainy days, pollution ... but they washed out,” Beecher said in a press release. “The one thing that was really significant was the amount of time between sunrise and sunset. Therapists should be aware that winter months will be a time of high demand for their services. With fewer sun time hours, clients will be particularly vulnerable to emotional distress. Preventative measures should be implemented on a case-by-case basis.” – by Amanda Oldt

Disclosure: Please see the study for a full list of relevant financial disclosures.