The issues here are beyond belief. MOST folks don't have any problems, but unfortunately certain personalities are attracted to high-tech and invasive procedures because of what might be called "psych issues". These folks, e.g. hypochondriacs, narcissistic persons etc., may not be recognized easily without a formal evaluation. Invariably, they do well on a trial, but will go bad after less than 4 months, and demand some sort of satisfaction, often getting the device removed or wanting immense amounts of medications and weekly visits in clinic. For all concerned, it is best not to court fire by missing this.