Ok so I have a ton of opinions on your sitch but I'm going to keep most of them to myself because most of them aren't particularly kind. But I'll give you some food for thought because that's the best I can muster without scaring you away from this board which I desperately think you need.
Lexapro the generic version of Prozac has been on the market for decades. Like decades, decades. I've been on Prozac. I've been battling depression for 2+ decades. Prozac made me more suicidal than I've ever been in my life. Which is a very common side effect. A well documented side effect. It didn't change me, it affected my brain chemistry in a way that deeply affected what was already there. What you are purporting is that SSRI's completely changed your W's personality or has made her so manic she's acting completely out of character. I don't think that an internet search and a couple of doctor friends are really the end all be all on that. Unless she is undiagnosed bi-polar honestly what you're saying isn't far off from a conspiracy theory and finding a scape goat isn't going to help you or your sitch in any way. And frankly as a woman who's been on MANY, MANY kinds of anti-depressants over the years this feels vaguely insulting. Like women have so little control over their own thoughts and little lady feelings that obviously it must be the crazy lady drugs.
Did you ever consider that this is the first time in years your W has felt like herself? Is there a chance your W has been battling with depression her entire life and this is the first time she's actually felt like herself in a very, very long time, if not ever?
I'm not saying that her being going at night all the time is OK, but if you're "stuck" with the kids at night, who's "stuck" with the kids during the day when they're awake almost the whole time?
Also, you're trying to make a soft science methodolgy a quantitative process. It doesn't work that way. The purpose of the method isn't to trick your wife into wanting to stay married. It's to teach you how to handle the crisis so you stay sane and are able to be the stability your kids need in this process. So while we're on that topic. I see a whole lot about W and the MR I see very very little about you. So what are you 180s in this process?
You can take or leave what I have to say with a grain of salt but you've left a lot of information out of this particularly about your MR and you specifically that leads me to follow my gut and my gut with guys who blame problems on everything but themselves usually get my hackles up. Maybe my vibes are off about this and it's simply because you haven't had the time to explain better. I'm hoping you can offer some clarity so I can be a little more supportive and a little less accusatory.