TVStudies have tended to find that watching more TV is correlated with higher levels of depression, but is that just because TV is so boring?

A recent review published in the New England Journal’s Journal Watch for Psychiatry suggests that the link might in part involve the fact that watching TV at night exposes you to blue and white light, which is particularly good at disrupting your circadian rhythms.

Just as getting bright light, particularly bright blue light, in the morning is good at helping you to establish strong circadian rhythms, getting light at night is good at disrupting them.

The authors cited a study that showed that even relatively low levels of blue and white light (equivalent to levels from watching TV) resulted in an increase in “depressive equivalent” behaviors in rats.

Bedrosian TA et al. Nocturnal light exposure impairs affective responses in a wavelength-dependent manner. J Neurosci 2013 Aug 7; 33:13081. (http://dx.doi.org/10.1523/JNEUROSCI.5734-12.2013)