Many people are unaware of the differences between mental health professionals and may use the terms "psychologist," "psychiatrist," or "counselor" interchangeably. However, there are important differences that you should be aware of about each profession, such as years of training, qualifications and licensure, and areas of specialization. This guide will help you choose the best professional for you, based on your specific needs. Psychologists: a "psychologist" has a Ph.D.