He's had to take lithium for a number of years, and still might for mood and behavioral issues, I think it might just be a reflection of the form of bipolar disorder he has. I have a friend (for real) who is bipolar and even with medicine he does very questionable things all the time, in a sense Landis reminds me of him. And before looking up what he has (cyclothymia) I already figured it may have ties to being bipolar or a form of it. That's why I give him a pass.
A lot of this isn't really in his control - in my view, because of that, don't really feel right in harshly criticizing him over it because he isn't wired like the rest of us, it would be like oddly judging a wheelchair bound person for being too lazy to walk, we've been given an off switch some of those who are bipolar haven't. So, just like I've learned with dealing with my friend with some things just gotta let it slide and acknowledge it's not really in their realm of control (and believe me he does some really wild and agitating "what the hell were you think?!" things) , which granted is hard to do because we luckily have no idea what it's like.
I'm not saying feel sorry for him. Just, I don't get hating the guy for something he really doesn't have a strong control over for legitimate psychological reasons.