If you stay in your room with the windows closed for a long time... (I mean a very long time... i spent a good year locked up in my room doing homework in-front of my laptop screen...) can cause you to become depressed...

Since I spent along time though I constantly had suicidal thoughts ^^

You shouldn't be having that problem though... :D

Over at the ferrari factory they have windows and plants everywhere to keep the workers happy... maybe you should stick a plant in your room ^^