Many people get confused about what the difference is between psychologists and psychiatrists. The difference rests primarily in the fact that psychiatrists have a medical background, whereas psychologists do not. As a result, here in Manitoba, only psychiatrists can prescribe medication.
Psychiatrists first train in general medicine and then specialize in psychiatry. While some psychiatrists do ongoing therapy with patients, more and more psychiatrists are devoting their time primarily to doing psychiatric evaluations in order to determine diagnosis and what, if any medication, is recommended.
Clinical psychologists, on the other hand, spend their entire training learning how to assess psychological problems and how to do therapy. Their practical focus is on doing assessments, therapy or both. A family doctor is most likely to refer to a psychologist when a patient needs therapy, whereas, they are most likely to refer to a psychiatrist when there has been difficulty determining what the correct diagnosis is and/or when there have been problems sorting out what medication would work best.