How old do you have to be to admit yourself to a mental hospital?

You’re going to have to be more clear here. Are you talking about a residential facility or the psych ward? Either way, if you’re under 18 your parents need to admit you (or if you say you’re suicidal or homicidal someone else will). And again, what does mental facility mean. Are you talking about a hospital psych ward or a residential treatment? Generally they do not keep people long term unless there’s something seriously wrong. And again it depends. Most people who are severe enough to go into a residential facility will be taking some kind of medication. And I repeat, it depends on where you go. Some times your parents can check you out (or you can check yourself out if you’re over 18), some times only a doctor can check you out. Honestly, it is rare for a person to be checked in long term without the parent approving it or asking for it. This is not a simple question…