New research says nighttime light exposure increases the likelihood of developing psychiatric illnesses, including anxiety, bipolar disorder, PTSD, and self-harm.
Anxiety and depressive disorders were the most prevalent mental illnesses, affecting one in eight individuals, or 970 million worldwide, in 2019.
Due to the COVID-19 pandemic, the number of individuals who suffer from anxiety and depression significantly increased in 2020. Initial projections indicate a 26% and 28% increase in anxiety and severe depressive disorders in just one year.
Although there are effective prevention and therapy methods, most of those suffering from mental illnesses do not have access to them.
The high number of mental illnesses and inadequate access to proper mental health care calls for a cooperative mission for the nation, and the study published in the journal Nature Mental Health also revealed a crucial non-pharmacological method for lowering the incidence of psychosis: increasing exposure to daylight.
High light exposure at night raised the risk of depression by 30%, but high levels during the day reduced the risk of depression by 20%.
Self-harming behavior, psychosis, bipolar disorder, generalized anxiety disorder, and PTSD showed similar outcomes.
These results suggest that avoiding light at night and seeking greater light during the day may be a potent, non-drug way to lessen major mental health problems.
"Our findings will have a potentially huge societal impact."-Associate Professor Cain
When people realize that their light exposure patterns significantly impact their mental health, says Cain, who led the study, they may make easy efforts to improve their wellness. The goal is to get brilliant light during the day and complete darkness at night.
Diving inside the study
The 86,772 people in the research were all drawn from the UK Biobank, and their exposure to light, sleep, physical activity, and mental health were assessed.
According to Cain, the effects of night light exposure were unaffected by demographics, physical activity, the time of year, or occupation.
Our biological systems have been flipped upside down by humans in contemporary, industrialized times, and our brains have evolved to function best in intense light throughout the day and then in nearly complete darkness at night.
He concludes: "Humans today challenge this biology, spending around 90 percent 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."