Recent study has indicated that exposure to light during night can triggers symptoms of depression. The study showed that interference in light-dark cycle is taking toll on mental health of the people. People who work night shifts or people who watch TV late night could be harming their health.

Research team led by Laura Fonken, a graduate student in psychology at Ohio State University, used animal models to study the impact of light-dark cycles. It was found that mice that were kept in light for 24 hours a day showed symptoms of depression.

Research team used 24 male laboratory mice for the research. Half of the mice were kept in light for 16 hours a day and darkness for 8 hours, while other half were kept in 24 hours of light. Half mice had opaque tubes in their units through which they could escape light any time while the other half had lighted tubes to escape.

Tests revealed that mice housed in constant light showed more depressive-like symptoms as compared mice that are kept in normal light-dark cycles.

Co-author Randy Nelson, a professor of neuroscience and psychology at Ohio State 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.”