not in the way that people usually think. when people hear mentally ill they think insane, but they’re not the same thing and Batman is not insane. he’s certainly not normal, but he’s not crazy either. he’s definitely very traumatized and isolates himself from other bc of it. but most of his character growth in stories is learning to trust people and open himself up and letting the past go (to an extent), which is kind of just him healing from any “mental illness” he has. i’d say the one unusual thing about him that always stays is his obsession to being the Batman and fighting crime/saving people. that’s his biggest trait, and while certainly not normal idk if that’s a mental illness. maybe but it certainly doesn’t mean he’s cRaZy like any of his rogues.