SAD Lights and Photosensitive Areas of the Brain

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I am considering purchasing a SAD (Seasonal Affective Disorder) light. When searching the world wide web, I came across the "Valkee Bright Light Headset" ( http://www2.valkee.com/uk/ ). There is some research behind it (see http://www2.valkee.com/uk/evidence/science/ ), but all of this research was done by people associated with the manufacture of this device. I have found a few other news reports about this device on the web, but I have not located any independent reviews. Moreover, I still have a hard time believing that sunlight can pass through hair, scalp and skull, and into the human brain.

Has anyone else heard about this device or used it? I am particularly interested in comments from people who know a lot about human anatomy and neurology or neuroscience.

Thank you, in advance, to all who respond.

I don't know about that particular light, but in general, yes, light therapy works well for some individuals with mood disorders. One precaution is if you are bipolar, rather than unipolar depressive- light therapy has been known to induce hypomania/mania in some. The reason light therapy seems to work for some individuals' depression is because there have been lots of recent findings regarding circadian rhythm abnormalities in mood disorders. For depression, light can "phase shift" the sleep cycle to a more typical pattern, rather than dealing with insomnia, hypersomnia, or awakening too early.

As for how the light therapy works, the photons of the light are just absorbed into the skin and through the eyes. Photons are microscopically small. The photoreceptors of the eyes play an especially big role in regulating circadian rhythms within the brain's hypothalamus/suprachiasmatic nucleus, because the retinal photoreceptors go straight to the brain for visual processing, via the optic nerve. Our brains release the sleep-inducing chemical melatonin at specific times of the day, and these times all are regulated with our light-dark cycle and natural circadian rhythms. And keep in mind that our bodies create vitamin D naturally through the absorption of sunlight.

If you have severe depression, light therapy alone might not work on alleviating your symptoms. But light therapy can also be a great add-on therapy to anti-depressants and/or CBT. Definitely talk about it with your psychiatrist/therapist if you are interested in giving it a try!

Aside from the fact that the idea of light being able to pass through the ear canal to the brain is ludicrous. Do not always believe the 'scientific evidence' that is posted on a products website. It is in their interest to look good.
Although I have not personally checked ALL of the references, I read some of their 'evidence'.
At first glance the Valkee website is impressive and for those with no biology background the evidence is very convincing and professional looking. But it is WRONG! Little in the way of peer-reviewed papers, questionable scientific methodology, and flimsy evidence with no definite links to fully back up their claims.
Yes, I do have a biology background (BSc Molecular and cellular biology), and the idea of light being able to physically pass through the ear and into the brain, and then magically affect proteins in multiple sites in the brain, is very, very wrong.
SAD is treated by light therapy, yes. But this involves light through the eyes, which mimics the sunlight we receive during the sunnier times of year. I recommend you look into buying an actual light box. Try finding an online forum for those with SAD, and see what they recommend.

Just to clarify, I work a lot of evening and night shifts, so I my primary interest in SAD lights is for regulating circadian rhythms. I understand the principles behind traditional SAD lights, but the people behind this particular (expensive) device are making three (extraordinary) claims. First, in addition to the regions of the brain associated with vision, there are other areas of the brain containing photosensitive cells. Second, bright light (such as sunlight) can reach these areas by passing through the hair, scalp and skull. Third, light directed through the ear canals (where the skull is thin) is very effective at stimulating these photosensitive cells. It has been many years since I last studied human biology, but I have a really hard time believing these claims.