Too much light at night could be making us more depressed, a study has warned.
By Andrew Hough
Published: 8:26AM BST 23 Oct 2009
For many, the harsh, bright glare of fluorescent street lights or office blocks which remain lit overnight has led to sleepless nights and subsequent bad moods.
“The ability to escape light seemed to quell the depressive effects,” said Laura Fonken, the study’s lead author.
“But constant light with no chance of escape increased depressive symptoms.”
Miss Fonken said the results provide additional evidence that the use of artificial light at night may have harmful effects on health.
“This is important for people who work night shifts, and for children and others who watch TV late into the night, disrupting their usual light-dark cycle,” she said.
The researchers also said many hospital wards are brightly lit all night, which may add to the problem of in-patients.
Co-author Prof Randy Nelson, a neuroscience expert, said the results suggested more attention needed to be focused on how artificial lighting affects emotional health in people.
He said: “The increasing rate of depressive disorders in humans corresponds with the increasing use of light at night in modern society.
“Many people are now exposed to unnatural light cycles, and that may have real consequences for our health.