Hello and welcome to Healthcare Magic. Thanks for your query. I appreciate your concern regarding your girlfriend s psychological problems. Firstly, I would like to mention that a diagnosis of Paranoid Personality Disorder is a clinical diagnosis and has to be done by a psychiatrist or a psychologist after a detailed history and psychological assessment. Merely exhibiting symptoms of being mistrusting or extra-cautious may not warrant the labelling of a personality disorder. In case, a diagnosis of a paranoid personality disorder is confirmed, then treatment is often challenging. It requires long term psychotherapy or sometimes, medication, and is usually not curable. If you feel that your girlfriend s symptoms are causing major problems between you, I think that the best way to tell her is that since both of you are having difficulties, it would be a good idea to seek professional help to sort out the difficulties. The psychologist or psychiatrist can then assess her to see if she has any symptoms of a paranoid personality disorder. Wish you all the best. Regards, Dr. Jonas Sundarakumar Consultant Psychiatrist