Disruption of circadian rhythms due to chronic constant light leads to depressive and anxiety-like behaviors in the rat.

Highlights: [•] Constant light alters temporal patterns of c-Fos in the suprachiasmatic nucleus. [•] Chronic constant light disturbs the overt expression of activity and hormonal circadian rhythms. [•] Rats exposed chronically to constant light develop depressive like symptoms characterized by low sucrose ingestion. [•] Extended light at night can alter the activity of the biological clock and lead to depression. [ABSTRACT FROM AUTHOR]