This could help treat SAD too

This is one of the cooler environmentally friendly technologies that will be coming our way soon - Hybrid Solar lighting. The idea is that a satellite-dish-like mirror mounted on the roof tracks the sun's position across the sky and captures the light with great efficiency and transmits it via plastic optical fibre to the rooms below (augmenting the artificial lights). This is suited well to single story buildings (as the fibres only transmit the light well up to 50 feet). You'll even enjoy the nice orange glow that accompanies sunrises and sunsets. Make sure to view the video at the link.

SAD is Seasonal Affective Disorder