There are some psychotherapists who go into the field of psychiatry, but it requires more education, medical school and a residency because a psychiatrist is a medical doctor. They are knowledgeable about the human body and its processes. They are trained to understand how chemical imbalances may be treated with medication. Without medical training about the human body (as opposed to the mind, which is a psychologist’s area of focus), a psychotherapist cannot be a psychiatrist and cannot prescribe medication. Most are qualified, however, to give patients a diagnosis and refer them to a psychiatrist.