Psychologists are people who have either a Ph.D. (Doctor of Philosophy) or a Psy.D. (Doctor of Psychology) in a field such as clinical or counseling psychology. In some cases, a psychologist may have an Ed.D. (Doctor of Education).
To get a Ph.D., Psy.D., or Ed.D., a person must go to graduate school. Graduate programs in clinical or counseling psychology usually last about 5 to 6 years. During that time, psychologists receive extensive training in the assessment and treatment of various psychological disorders. Depending on the type of training received, each psychologist is going to have his or her own beliefs and ideas about the origins of psychological disorders and how to treat them.
Psychologists generally do not prescribe medication (although they are able to in some states).