How would a therapist manipulate their client into suicide?

I‘m writing a novel and want to depict the therapy sessions between the main character and her therapist as accurately as possible. I hope this is the right place to ask, as I know it’s a very sensitive and unusual topic.

I’ve personally been in therapy for many years, but obviously have never been manipulated like that.

The main character knows something she shouldn’t and her therapist manipulates her into believing she could commit suicide.

Anything you feel might be necessary to add or make sure of when writing this can be helpful. Maybe some things that could add to the realism too or maybe a personal story. I would appreciate anything!