Suave

Your fear is quite justified. Once you've been admitted to an asylum, it's much harder to prove yourself legally sane than it is under normal circumstances. Your being in an asylum alters the perceptions of those around you, and any actions that are not considered completely ordinary may be taken as evidence of your "insanity". Once someone has been given a label, they're expected to adhere to that label, in this case, that of being insane.