Whats the difference between a psychiatrist and a psychologist?

Depending on the specialization of the psychiatrist, he or she may have studied human behaviour from a biological/chemical perspective. (This would be why many approach mental illness by first prescribing medications.) Psychiatrists do have education in human behaviour and pathologies, but not as much as a psychologist. A cognitive-behavioural psychologist, for example, will approach a patient's condition (whether or not they are prescribed medications by a physician) from a behavioural standpoint, addressing thoughts, behaviours, actions and perceptions as they relate to mental illness. They are generally *experts* in research techniques as well, as with psychological study, conclusions cannot simply be drawn from numbers and data may be interpreted subjectively. When embarking on a project (study), they have much more to "prove"; it is much harder to defend your research/conclusions when "answers" are not finite. Psychologists are often recruited to design and conduct studies/research in fields other than psychology.