Honestly, being in prison (or an institution) is probably the best chance he has at mentally developing.
He'll be alone in a cell, with no internet access, no video games, no MLP cartoons, no toy collection, no income, no "gal pals", and forced to eat the same food as the rest of the prisoners, no one who's going to coddle or humor him or be at his beck and call for his childish demands - he'll basically be forced to just sit and stare at a wall all day and actually reflect on his "life" up to this point.
Right, stuff like thinking that you can just take some hormone pills you bought off the internet and magically grow a vagina just reminds me of how much I underestimate how delusional he is.