Committing someone to a mental health facility against their will is never an easy thing to do. But if they're truly ill, then they need to get help. If it turns out that they weren't ill, then you can have faith that the doctors will eventually figure it out and release them...right?
Well, if the results of this 1973 experiment are to be believed, I wouldn't count on it.
However, once inside the facility, they acted completely normal and continually told the doctors that they felt fine.
Despite evidence of having sane people in front of them, each member of the team was forced to admit to having a mental illness. They then had to agree to take anti-psychotic drugs as a condition of their release. Nearly all of them were "diagnosed" with schizophrenia. The average time from admittance to release for each of the pseudopatients was 19 days.