Tom is giving you excellent advice, both in taking care of Ken and taking care of yourself.

I watched my former father in law going thru much the same problems when my former mother in law had Alzheimers -- The entire family encouraged him to get involved with caregiver support groups and the main benefit there was that he found he was not alone -- He had others going thru the same problems to talk to.

In re: Ken and the anti-depressants, there are many different types and they have different effects (and they take a while to build up in the body to the point where they are effective) -- Since he seems to have had a very negative affect, he should be watched carefully by his physician or therapist at first (which also has the side benefit of getting him out of the house more often.

Please consider getting friends or family or even hired help to keep Ken company while you take some time off to meet with friends or go to movies or swimming pool or whatever -- You need a break to let off some steam.

Pete