Suicide is a no-no for ANYONE! Geesh! Do you have to bring up Catholicism at a sad time like this?
I don't know about depression ---I always thought suicide was usually a result of "despair", which Catholics aren't supposed to do. I guess some people have clinical depression ---a real medical condition but a guy from work I once knew really didn't fit the image you get of depression ---he would go to work every day, laugh, joke at lunch but one day he just went home and killed himself.