The question sounds like the setup for a joke, but it's an important difference to understand whether you are a student of psychology or a consumer searching for a mental health provider. The terms "psychologist" and "psychiatrist" are often used interchangeably to describe anyone who provides therapy services. While psychologists and psychiatrists both conduct psychotherapy and research, there are significant differences between the two professions.
Education, Training, and Credentials
The simplest answer lies in the educational background required for each profession. A psychiatrist has a degree in medicine and a psychologist has a doctoral-level degree in psychology. However, there are a number of other distinctions that make each profession quite unique.
Psychologists receive graduate training in psychology and pursue either a Ph.D. (Doctor of Philosophy) or Psy.D. (Doctor of Psychology) in clinical or counseling psychology. Doctorate programs typically take five to seven years to complete and most states require an additional one or two year long internship in order to gain licensure. Other states require an additional year or two of supervised practice before granting full licensure.
The title of "psychologist" can only be used by an individual who has completed the above education, training, and state licensure. Informal titles such as "counselor" or "therapist" are often used as well, but other mental health care professionals such as licensed social workers can also claim these titles.
Psychiatrists are physicians that have specific training in the assessment, diagnosis, treatment, and prevention of mental illnesses. In order to become a psychiatrist, students first earn an undergraduate degree before they attend medical school and receive an M.D. After finishing their medical training, they also complete an additional four years of residency training in mental health. Some also receive additional training in a specific area of interest such as geriatric psychiatry, child and adolescent psychiatry, addictions, and other areas.
A second important distinction between the two careers is that psychiatrists can prescribe medications, while in most states psychologists cannot. However, there has been a recent push to grant prescribing powers to psychologists. Some states such as New Mexico and Louisiana now grant prescribing privileges to medical psychologists holding a post-doctoral masters degree or equivalent in clinical psychopharmacology.
Kevin McGuinness, chairman of the Commissioned Corps Mental Health Functional Advisory Group, writes, "For those interested in a career in psychology as a prescriber, it is important to know that certain federal employees and uniformed commissioned officers (Army, Air Force, Public Health Service, Navy, etc.) that are licensed in one state as a medical psychologist may prescribe an any other state to which they are assigned by the federal government."
Which is Better?
If you are considering a career as a therapist, you will need to determine which career path is best for you. Are you interested in conducting psychotherapy, administering psychological tests, and conducting research? If so, a career as a psychologist may be the best choice for you.
On the other hand, if you have an interest in medicine and want to be able to prescribe medications to your patients, a career in psychiatry might be your ideal choice.
If you do not want to invest five to eight years in graduate training, consider pursuing a career as a licensed social worker or counselor. These professionals are also qualified to provide mental health services depending up training and experience. Both social work and counseling typically require two or three years of graduate study.
Psychiatric nursing is another great career option for students interested in medicine. Advanced Psychiatric Nurses hold a master's degree or higher in psychiatric-mental health nursing and are able to assess patients, diagnose disorders, provide psychotherapy, and prescribe medications.
K.M. McGuinness, personal communication, May 19, 2011.
Cloud, J. (2010). Psychology vs. Psychiatry: What's the Difference, and Which Is Better? Time. http://healthland.time.com/2010/10/01/psychology-vs-psychiatry-whats-the-difference-and-which-is-better/
Richmond, R. L. (n.d.) Psychology and Psychiatry. A Guide to Psychology and Its Practice. http://www.guidetopsychology.com/psypsy.htm