Influence of Light Exposure on Cerebral MAO-A in Seasonal Affective Disorder and Healthy Controls Measured by PET

One subgroup of SAD patients and healthy controls respectively will receive bright light therapy using an artificial white light source (PhysioLight LD220 by DAVITA®, www.davita.de/shop/lichttherapiegeraete/lichtduschen-tageslicht/physiolight-ld-220.html) with full-spectrum 10.000lux light intensity. The treatment will be applied 30min per day at a distance of about of 50cm, preferably in the morning, during 3 weeks.

The second subgroup of the SAD patients and healthy controls will receive a non-biologically active light source (\<400nm or \>500nm). Here, the lamp will have largely similar shape and size as compared to the therapeutic device, but the fluorescent tube with the high light intensity will be replaced by an ordinary bulb.