This is quite a good watch. The transition from "who dunnit" to actual psychological thriller is done tastefully, and retrospectively, you can realize, that there were respective hints here and there. Holland portrayed his role quite well, too, in fact sometimes the depiction felt somewhat relatable, even though I have bipolar type 2, which is a very different thing. But I do know Danny's feelings to extent.
I do have one issue, though, and it's with the court hearing.
Or rather with the fact, that the most obvious reasoning (the one involving Adam) was used so late in the game. I understand why the matter was not pushed with Danny before he even accepted the fact that he has multiple personalities - no issues with that, but after the hearing started, when they needed to prove the abuse, they could have just started with the questioning of who was Adam and whether he actually existed.