look up reversing brain washing or better yet…
https://libertyforcaptives.com/2013/10/12/how-to-rescue-someone-from-a-cult/
Don't forget about when a prisoner falls in love with captor.
Seriously. The survival mechanism is deep. Children have been brainwashed since daycare. Trusting you is very important. Slow simple steps. Ask them what is amok with what they know.