Unlike psychiatrists, who have extensive training in the biological components of mental disease, psychologists are trained more in the psychological and/or behavioral components of mental illness. Psychologists receive their degrees, either Doctor of Philosophy — Ph.D. or Doctor of Psychology — Psy.D., from one of 750 accredited colleges or universities.
All psychologists must first complete four years in a Bachelor of Arts or Science program before enrolling in a Ph.D. or Psy.D. program. They are required to fulfill a minimum of 3 full-time academic years of study and a one-year, practical internship in an in-patient or out-patient setting. This one year is also known as a "post-doctorate".
The Ph.D. in psychology may be in "clinical" psychology (with a focus on research and practice), or "counseling" psychology (with a focus on practice in less pathological populations). The Psy.D. degree places emphasis on practice rather than research, and the program emphasizes training psychologists who work with patients, as opposed to research groups.
Psychologists today often focus on cognitive-behavioral therapies (talk), and do not have as intense a training regimen in the biological components of mental health disease as psychiatrists.
Many become researchers with emphasis on statistical analysis. During their training programs psychologists are taught about human development, individual differences in behavior, dysfunctional behavior, and professional standards and ethics.
Psychologists work in a variety settings including hospitals, clinics, private practice, schools and universities. Many patients with problems such as eating disorders, mild depression, alcohol or drug addiction are often referred to psychologists for therapy sessions, but also see psychiatrists for their drug treatments.