Raise your hand if you've had this happen:

I've gained and lost friends when changing medications sometimes for different health problems. It's just one of those things that happens. They go, dude you seem a little off, what the hell and I go, trying to adjust to some stuff and then they refuse to believe it and go awol. Which makes you wonder if they liked you for you vs liked you for who you were under a particular pill. You're still you of course at the bottom of all of it but they treat you like you are possessed by a demon or something.

If you or some one else find yourselves fighting a shit ton more often and neither understand why the other is behaving that way it could be that something is chemically off. That doesn't really help anyone during the mess but it feels better than just assuming it's because the person who was your friend, lover, neighbor or whatever was just a superjerk.
People pick up on these little things and react accordingly but usually incorrectly.