Eye Movement Desensitization and Reprocessing (EMDR) therapy is an integrative psychotherapy approach that has been extensively researched and proven effective for the treatment of trauma. EMDR is a set of standardized protocols that incorporates elements from many different treatment approaches. To date, EMDR therapy has helped millions of people of all ages relieve many types of psychological stress.  It is designated as an effective treatment by the American Psychiatric Association, the World Health Organization (WHO), the U.S. Department of Veterans Affairs and Department of Defense, the U.S. Department of Health and Human Services (HHS) and many other international health agencies.

The EMDRIA website says,

When a person is very upset, their brain cannot process information as it does ordinarily. One moment becomes “frozen in time,” and remembering a trauma may feel as bad as going through it the first time because the images, sounds, smells, and feelings haven’t changed. Such memories have a lasting negative effect that interferes with the way a person sees the world and the way they relate to other people. 

EMDR seems to have a direct effect on the way that the brain processes information. Normal information processing is resumed, so following a successful EMDR session, a person no longer relives the images, sounds, and feelings when the event is brought to mind. You still remember what happened, but it is less upsetting. Many types of therapy have similar goals. However, EMDR appears to be similar to what occurs naturally during dreaming or REM (rapid eye movement) sleep. Therefore, EMDR can be thought of as a physiologically based therapy that helps a person see disturbing material in a new and less distressing way.