Depression (major depressive disorder) is a common and serious medical illness that negatively affects how you feel, the way you think and how you act. It can feel so powerful; making people believe that life is not worth experiencing.

Charlie Brown and Lucy were standing in the back of the classroom.  The dialogue (to the best of my memory) went something like this:

Charlie Brown:  Where were you yesterday? I saw your desk was empty.
Lucy:  I was homesick.  I had a cold.
Charlie Brown:  There were a lot of empty desks.  There must have been a lot of kids with colds yesterday.