Looking for old movie with hypnosis scenes

[beast54321]

I can’t recall the name.  There was a movie I watched LONG ago, movie likely filmed in the 70’s.  I think it featured a group of female college students, or a family with a female college student, that was captured/whatever by a group of cultists.  At one point one of the students was hypnotized by the cult and left in a room or basement with a teacher/authority figure.  The young woman was sitting on a chair sitting with her eyes either shut or entranced. The teacher shook the girl trying to snap her out of it, but she just slowly reverted to a stiff sitting position.

Does anyone remember a movie like this?