Light at Night Tied to Higher Risk for Mental Health Disorders

However, daytime, natural light may offer a protective effect

By Lori Solomon HealthDay Reporter

TUESDAY, Nov. 28, 2023 (HealthDay News) — Avoiding light at night and seeking natural light during the day may be an effective way to improve mental health, according to a study published online Oct. 9 in Nature Mental Health.

Angus C. Burns, Ph.D., from Monash University in Melbourne, Australia, and colleagues examined associations between daytime and nighttime light exposure with the risk for psychiatric disorders and self-harm. The analysis included 86,772 adults (57 percent women).

The researchers found that greater nighttime light exposure was associated with an increased risk for major depressive disorder, generalized anxiety disorder, posttraumatic stress disorder (PTSD), psychosis, bipolar disorder, and self-harm behavior. Greater daytime light exposure was associated with a reduced risk for major depressive disorder, PTSD, psychosis, and self-harm behavior, independent of nighttime light exposure. When adjusting for sociodemographics, photoperiod, physical activity, sleep quality, and cardiometabolic health, the findings persisted.

“Avoiding light at night and seeking light during the day may be a simple and effective, nonpharmacological means of broadly improving mental health,” the authors write.

Several authors disclosed ties to industry.