SYDNEY (Xinhua) — A new study led by researchers from Monash University has found that greater nighttime light exposure can lead to an increased risk of mental disorders, such as anxiety and PTSD.
According to the research published Monday in the Nature Mental Health journal, the research team conducted the “largest to date” cross-sectional analysis of light, sleep, physical activity, and mental health, which involved more than 86,000 participants.
Among those exposed to high amounts of light at night, the risk of depression increased by 30 per cent, while the participants who were exposed to high amounts of light during the day saw their risk of depression down by 20 per cent.
Similar patterns of results were detected for self-harm behavior, psychosis, bipolar disorder, generalised anxiety disorder, and PTSD.
The study suggested that avoiding light at night and seeking light during the day could be an effective and non-pharmacological method for improving mental health.
Sean Cain, leader of the research project and associate professor at Monash University, noted that the impact of night light exposure was independent of demographic, physical activity, season, and employment. “And our findings were consistent when accounting for shift work, sleep, urban versus rural living, and cardio-metabolic health,” said Cain.
He pointed out human brains evolved to work best with bright light in the day and then with almost no light at night.
“Humans today challenge this biology, spending around 90 per cent of the day indoors under electric lighting which is too dim during the day and too bright at night compared to natural light and dark cycles. It is confusing our bodies and making us unwell,” the expert added.
