More than 500 brands of psychotherapy exist, with new ones springing up on a nearly monthly basis. Although a handful of these neophyte treatments have been tested in scientific studies, it is anybody’s guess whether the others actually work.

Over the past 15 years or so, one of these new kids on the therapy block has stood out from the pack for the remarkable attention it has received from the media, practitioners and mental health consumers. This treatment carries a mouthful of a label—eye movement desensitization and reprocessing—and it has made an impressive splash on the psychotherapy scene. Not surprisingly, most therapists refer to it simply as “EMDR,” and we’ll do the same here.

Like some other psychotherapies, EMDR was the brainchild of serendipity. One day in 1987 Francine Shapiro, a California psychologist in private practice, went for a walk in the woods. She had been preoccupied with a host of disturbing thoughts. Yet she discovered that her anxiety lifted after moving her eyes back and forth while observing her surroundings. Intrigued, Shapiro tried out variants of this procedure with her clients and found that they, too, felt better. EMDR was born.

After an initial published study in 1989, EMDR became the focus of dozens of investigations and scores of presentations at professional conferences. Shapiro initially developed EMDR to help clients overcome the anxiety associated with post-traumatic stress disorder (PTSD) and other anxiety disorders, such as phobias. Nevertheless, therapists have since extended this treatment to a host of other conditions, including depression, sexual dysfunction, schizophrenia, eating disorders, and even the psychological stress generated by cancer.

EMDR therapists ask their clients to hold the memories of anxiety-provoking stimuli—for example, the painful memories of a frightening accident—in their minds. While doing so, clients track the therapist’s back-and-forth finger movements with their eyes, much like a person in an old Hollywood movie following a hypnotist’s swinging pocket watch. EMDR proponents have invoked a dizzying array of explanations for the apparent effectiveness of the lateral eye movements: distraction, relaxation, synchronization of the brain’s two hemispheres, and simulation of the eye movements of rapid eye movement (REM) sleep have all emerged as candidates. In conjunction with their therapists, EMDR clients also learn to replace negative thoughts (such as “I’ll never get this job”) with more positive thoughts (such as “I can get this job if I try hard enough”).

Few psychological treatments have been as widely heralded as EMDR. Some EMDR proponents have called it a “miracle cure” and “paradigm shift,” and ABC’s 20/20 proclaimed it an “exciting breakthrough” in the treatment of anxiety. More than 60,000 clinicians have undergone formal training in EMDR, and the EMDR International Association (EMDRIA), a group of mental health professionals dedicated to promoting the technique, boasts more than 4,000 members. The organization estimates that this procedure has been administered to approximately two million clients. Moreover, in some American cities, psychotherapists proudly list their certifications in EMDR on their Yellow Pages advertisements. But does it work?

The answer is not entirely straightforward. As with all psychotherapies, one can look at the question of whether EMDR “works” in several different ways. Here we will address three important variants of this question:

Does EMDR work better than doing nothing?
Yes. Numerous controlled studies show that EMDR produces more improvement than absence of treatment, at least for alleviating the symptoms of civilian PTSD, such as those triggered by rape. The evidence that pertains to EMDR’s efficacy for other anxiety disorders is promising but preliminary. EMDR’s effects are most marked on self-reported measures of anxiety; its impact on physiological measures linked to anxiety (such as heart rate) is less clear-cut.