ADD husband has two different personalities?

My husband--the guy largely in denial about his condition, takes an ADD med but will not enter into any sort of ADD therapy, etc.--doesn't seem to have made a habit out of taking his medication. Before we separated, I would notice that when things would get stressful, he would have two very different personalities: one who was loving, sweet, honest, generous, and understanding, and another who was a stubborn, selfish, illogical, pathological liar.

At the time, I wondered if it was due to an antidepressant he had been on. I did *not* like his personality on that--nasty, surly, just a total full-of-himself jerk, and good luck to anyone who pointed any of that out to him, even carefully and kindly, because he'd only get nastier and throw lots of anger and blame back on you.

Now, it seems that he doesn't believe me, but I can *tell* when he shows up for some meeting or other and hasn't taken it. With the med he's an *entirely* different person than without, and is actually reasonable and pleasant to deal with. Without, not so much. The difference is much more marked than before he went on it. Now when he's kind, etc., he's very kind. When he's not, he's *VERY* not. Watching him switch between the personalities is really creepy. It's like a switch is flipped. ADD med wears off or ramps up, and you get an entirely different person in very short order.

I suspect that he's still on the Jekyll-and-Hyde antidepressant to which he's reacting very badly, and that the ADD med "counteracts" it to an extent. Has anyone ever noticed something like this before, or am I totally up a tree?

I'm asking not because I'm trying to put the marriage back together (gave up on that *months* ago and moved on). It's just that I've noticed that whenever we meet to discuss anything, when he doesn't take his ADD med, he's SO difficult and unreasonable that it's entirely counterproductive. I'm thinking that, from now on, to make the divorce go more smoothly, whenever I show up to a meeting and notice that he's forgotten to take his ADD med, I may just--as carefully and as kindly as I can--call that session to a halt and reschedule, even if I have to make up some stupid emergency that pulls me away instead of telling him the real reason. But I'm wondering if that's going to cause as many problems as it solves if he figures it out. He's so oppositional and reactionary when he's off that ADD med.

Does any of the above make any sense? It's difficult to convey, and I feel like I just can't win for losing.