What is the Difference Between a Psychiatrist and a Psychologist? (USA)

This answer reflects the situation in the United States.

A psychiatrist is a medical doctor who can prescribe medication.

Psychologists typically hold doctorates; however, they do not attend medical school and are not medical doctors. Instead, they study human thought and behavior.

Both psychiatrists and psychologists can diagnose disorders and provide counseling and therapy; however, only a psychiatrist can prescribe medication.