There are several JW-psychiatrists/psychologists. Some will only take JW's for patients, others won't take JW patients at all. Of the ones who do see JW's I have read that some have broken doctor-patient confidentiality and talked to the elders about what the patient said. If the patient knows that is a possibility going in and agrees to it...well, to each his or her own! If it's done without the patient's knowledge or prior consent think of the harm that might be done. This is something to communicate to anyone who is considering getting professional help from a JW.
As far as mind control is concerned, ever hear of a double blind?
My suggestion is that you dig up the Awake! articles on depression from back in the '80's. They mention seeking professional help and they don't limit it to JW practitioners. There are suggestions and things to consider before seeking professional assitance in one of the articles, maybe if you presented that information to your JW it would do some good. At least it would show from their own publications that a non-JW practitioner is OK.