An wonderful English madrigal from 1598 by Thomas Weelkes goes
“To shorten Winter sadness
see where the nymphs with gladness
Falala lala lala
Falala lala lala”
And the nymphs go dancing and singing through the town making people happy.
The point is that human beings have known about “Winter sadness” for a long, long time. However, scientific research on SAD (Seasonal Affective Disorder) is still recent. We know that sunlight and artificial light helps, especially in the mornings, to “pace” your biological light cycle. Surprisingly enough, melatonin PLUS darkness at the right time of evening also helps — melatonin in the brain is triggered by sunset, the onset of night. Synching your wake-sleep rhythm to natural light is a key (called “sleep hygiene” in Cognitive Behavioral Therapy). And remember that for most of our evolutionary history humans were sunny hunter-gatherers in Africa, so bright natural sunlight makes sense also. Just like Thomas Weeks’ nymphs, music and dancing also make people happy.
But shining a light in your ear? Frankly I never thought about that until I read an article by a Finnish team led by Jurvelin et al (2014) suggesting that “Transcranial bright light treatment via the ear canals” might help SAD. The reason? There is not much tissue blocking bright light shone into the ear canals — as soon as you penetrate the ear drum and inner ear liquid, which is very thin and translucent, your bright light source affects the neurons of the ear canal and vestibular (balance) system. There are other medical mysteries having to do with the ear canal, such as the use of ice water to relieve visual half-blindness due to parietal damage. The fact is that nobody is quite sure why those ear tricks work, but they are interesting.
Jurvelin reports that after four weeks of 12 minute daily doses of light energy into the ear canals “all three patient groups showed significant decreases in their Beck Depression Inventory, Hamilton Anxiety Rating Scale and Hamilton Depression Scale – SAD version.
All groups should at least a 50% drop of symptoms using the Beck scale. However, one in four patients had “mild adverse events, including headache, insomnia, and nausea.” This is not unexpected, given that light stimulates the balance system in the inner ear.
So if you feel SAD during the winter, trying sticking a light in your ear — but not too much!