Dim lights at night linked to depression

COLUMBUS, Ohio, Nov. 18 (UPI) -- U.S. researchers say animal studies show exposure to even dim light every night may be enough to cause depression.

Researchers at Ohio State University in Columbus found female Siberian hamsters exposed to dim light every night for eight weeks showed significant changes in a part of the brain called the hippocampus.

The researchers say the brain changes may be a key to why the hamsters exposed to dim light at night showed more depressive symptoms versus hamsters exposed to a standard light-dark cycle.

This is the first time researchers have found that light at night -- by itself -- may be linked to changes in the hippocampus.

"Even dim light at night is sufficient to provoke depressive-like behaviors in hamsters, which may be explained by the changes we saw in their brains after eight weeks of exposure," study co-author Tracy Bedrosian says in a statement.

The study findings were presented in San Diego at the annual meeting of the Society for Neuroscience.