It's a fine drug that probably doesn't get used enough. So many people I know have a problem keeping weight off with the drugs. The SSRIs and bupropion don t cause weight gain. Exercise is an important part of the recovery phase from depression. In fact, should be a part of all of our lifestyles.
Depression can be a fatal illness.
I wouldn't fool around in the case of a moderate or severe depression with anything untried and untested. I personally prefer to avoid medications and professionally limit their use to cases where they're needed. The inability to function is a major tipofff, as are suicidal thoughts. The length of the process can vary. People are usually able to return to work or school, though feeling appropriately sad, a week or two after bereavement.