Science Fair Project Encyclopedia Psychiatry is a branch of
medicine that studies and treats mental and emotional disorders
(see mental illness). While any physician may prescribe the
medications used to treat various forms of mental illness,
psychiatrists are more extensively trained in differential
diagnosis of mental illness and keep up to date on the newest
treatment modalities for mental illness. The term alienist is an
old term for a psychiatrist, and the term shrink (from "head
shrinker") is a (sometimes offensive) slang term for a
psychotherapist. Note that psychiatry is practiced by
psychiatrists, psychology by psychologists. Psychiatrists are
medical doctors and may prescribe drugs. Psychology is the
broader study of behaviour and thought processes not just in the
context of mental health. Clinical psychologists specialize in
mental health and have extensive training in therapy and
psychological testing. They do not usually prescribe drugs. Mind
versus brain Psychiatric illnesses were for some time