Psychologists are health professionals who have training and expertise in human behavior and psychological health. Psychologists are not medical doctors, but they hold a doctor of psychology (PsyD degree) or doctor of philosophy (PhD degree) in clinical psychology, counseling, or school psychology.

Psychologists evaluate and treat people who have mental health problems, such as depression. Psychologists also provide counseling and other mental health services. Some states allow psychologists to prescribe medicine.

Psychologists are licensed in the state in which they practice.