What is the difference between psychiatry and psychology?
Historically, the sciences were considered a part of philosophy called natural philosophy, because they pertained to thinkers concerned with the state of nature. Psychology was that part of natural philosophy associated with human nature. As philosophers of human nature were primarily concerned with actions that could be judged as right and wrong, psychology was considered a moral science. This was the purview of philosophers who were contemplating the normal range of human behavior. Alternatively, abnormal behavior, more commonly known as psychopathology, was generally the purview of physicians. Those physicians consisted of either neurologists or general practitioners whose responsibilities included the general medical care of patients committed to asylums for the mentally ill. No special training existed in the diagnosis and treatment of mental illness. Expertise was therefore derived primarily from exposure to those types of patients and not by any specialized training. When science separated from philosophy with the introduction of the experimental method, the field of psychology also began to adopt an equally experimental approach. Psychology retained its status in the university as an academic discipline devoted to understanding how human behavior and the mind worked.
Freud, trained as a neurologist, was the first physician to develop and describe a method of therapy whereby the patient said whatever came to mind—called free association. The therapist would listen critically and link various dreams, memories, and stories that the patient related to him or her and provide an interpretation for the patient as to the unconscious meanings of the patient's narrative. Through these interpretations the patient developed insight, allowing the patient to make changes in both his or her attitudes and behavior so that he or she could be relieved of pain and suffering. Freud coined this method psychoanalysis. This was the beginning of modern psychotherapy. Freud was instrumental in expanding the treatment of mental illness in such a way as to take it out of the asylums and put it in the office. He also strongly believed that although psychoanalysis required very specialized training, a medical degree was not required to learn and practice the technique. Thus the door was opened to psychologists becoming clinicians rather than solely scientists and philosophers. Since that time universities and professional schools of psychology have expanded to train psychologists to become clinicians. Psychology students can choose a career track in either research or the practice of clinical psychology. A clinical psychologist typically has undergone 4 years of undergraduate education and 4 years of graduate education in psychology, followed by a 1-year internship in a mental healthcare setting, treating patients under the supervision of a senior psychologist.
Psychiatrists have a radically different educational path, having grown as a specialty out of the asylum system where physicians took responsibility for the general health care of the mentally ill who were confined to asylums. Psychiatrists begin studies in human anatomy and physiology as medical students. Graduating with a medical degree and the same educational background as all physicians, psychiatrists spend a year in an internship that may include psychiatry but must include medicine or some other medical rotation and neurology. After internship one spends an additional 3 years as a resident physician, treating patients in a variety of settings under the supervision of a senior psychiatrist. As physicians, psychiatrists are licensed to prescribe medications just as all physicians are. However, because of their specialty, they develop a singular expertise in using medications to treat mental illness.
-  the mental process of saying aloud whatever comes to mind, suppressing the natural tendency to censor or filter thoughts. This is a technique used in psychoanalysis and in psychodynamic psychotherapy.
-  an underlying motivation for behavior that is not available to the conscious or thoughtful mind, which has developed over the course of life experience.