As the dark, cold nights close in... is street lighting to blame for our winter blues?
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Street lights may be to blame for millions of us getting the winter blues.
Research found people with depression during the winter months were more likely to live in areas flooded with artificial outdoor lighting than places where the nights are darker.
Findings suggest chronic exposure to man-made outdoor lights – such as street lamps – can worsen moods.
One theory is outdoor artificial light tends to be more intense and less controllable than lights in our homes – therefore more likely to disrupt the body’s internal clock.
Around two million people in Britain are thought to have seasonal affective disorder (SAD), which can cause low mood, irritability, lethargy, difficulty concentrating and a decreased sex drive.
Some take antidepressants to cope, while others rely on light therapy – where a special lamp mimics the benefits of sunlight on the brain’s hypothalamus.
The hypothalamus controls melatonin production, a hormone that makes us tired. Lack of daylight triggers melatonin to be released and deprives the body of the feel-good chemical serotonin.
But the research, published in the journal Environment International, suggests SAD sufferers may be better off reducing their outdoor light exposure in the evenings.
Street lights in Canary Wharf. Research found people with depression during the winter months were more likely to live in areas flooded with artificial outdoor lighting
Data from around 40,000 men and women aged over 50 from the US, England, Northern Ireland and the Republic of Ireland was analysed. Researchers measured exposure to artificial light at night, matching it to depression rates.
Those in areas with the most nighttime light were more likely to experience mental health issues than those in the darkest areas.
In England, bright lights at night increased the risk of depression by an average of 16 per cent. In Northern Ireland, they increased the risk by 80 per cent.
Those in rural areas were more affected by artificial light. Researchers suggested this may be because they are more used to darkness the rest of the year.
Study author Professor Paola Zaninotto, from UCL’s department of epidemiology and public health, said: ‘Outdoor light exposure at night may be an overlooked environmental risk factor for depression in older adults, especially in rural areas.’
Daily Mail
