How can I help my father realize that he needs to get help for his depression?

I have exactly the same problem. My father is 87 and the stress of taking care of my mother's Parkinson's, incontinence, dementia, too weak to walk etc... has stressed him out to the point that he explodes or just cries. I am taking my mother to live with me but that really won't help his depression. Can't wait to see what others say. My father doesn't think "a pill" will help him, he doesn't understand that antidepressents are not relaxing pills that put you to sleep. He is old and hard headed and not willing to listen to what I have to say. I love him and just hate seeing him like this when I know an antidepressant could help him. I inherited my tendency to get depressed from him!