I think it is some of both but thoughts are guided mostly by perception so thinking you want to die because your best friend died; yeah, no med can bring your friend back, make you grieve less, but it can help you shift the perception that killing yourself is a good solution for you in response to your friend dying.

Feeling worthless because one doesn't have a job, when looked at "rationally" does not make sense; we do not have worth because we get up each morning and go to a crappy job and earn $10.12 an hour or because we get up each morning and go to a wonderful job and earn $100 an hour. That is all personal perspective and if a med allows me to look at my life more "rationally" then I say I'm "smart" enough to see that and work on figuring out what my real problem is (not that I feel worthless, but that I am not treating myself with respect and going after what I really want in life, the $100 an hour job :-) and how to make my life work better for me.