Psychologists who see patients with nightmares tend to search for an underlying disorder, such as depression, anxiety or trauma, and treat them for those problems rather than dealing with the nighttime symptoms.

But that isn't always the best way to approach the problem, says one prominent sleep disorder researcher, because without treating the nightmare itself, recovery from post-traumatic stress disorder and other problems can be prolonged.

"What many people don't realize is that nightmares can cause insomnia. And that lack of healthy sleep really gets in the way of healing, only perpetuating the trauma disorder, " says Dr. Barry Krakow, a psychiatrist and medical director of the Sleep and Human Health Institute in Albuquerque, N.M.

Krakow and others have been perfecting a technique first introduced by British researcher Ian Marks in 1967: imagery rehearsal therapy, in which patients will actually take a nightmare, rewrite it and practice it.

In a 2001 study Krakow published in the Journal of the American Medical Association, groups of sexual assault survivors found significant improvements in symptoms after using imagery rehearsal.

The severity of nightmares and post-traumatic stress disorder symptoms decreased in 65 percent of the 114 patients in the study, on a par with those receiving medication. The study also found that 79 percent of 62 crime victims who had similar image rehearsal therapy experienced a decrease in traumatic stress symptoms.

Participants were asked first to practice pleasant imagery exercises. Then, in later sessions, they were asked to rewrite their nightmares and "rehearse" the new dreams by using the imagery exercises, and were encouraged to practice the rehearsal therapy between five and 20 minutes a day.

Krakow believes that in some cases, even after a patient has undergone successful therapy for trauma, his chronic nightmares may continue, taking on a life of their own because an individual's thought patterns are stuck in a "bad sleep habit," like a groove in a record.

Because nightmares and insomnia often go hand in hand, patients who responded to image rehearsal therapy also slept better, and, consequently, felt better, enabling them to cope more effectively with daily stresses, Krakow says.

But the treatment doesn't require psychotherapy, and Dr. Thomas W. Sheridan thinks that' a concern.

Sheridan, a clinical psychologist on the medical staff at Allegheny General Hospital's Department of Psychiatry, believes that the content of nightmares - indeed of all dreams - must be respected and interpreted, not treated as if it were "some kind of noxious stimuli, triggering a conditioned response. Krakow is negatively defining a nightmare before asking what's its intention."

One of Sheridan's own patients, who asked not to be identified, said his approach was tremendously helpful to her own experience with a disturbing dream.

"I wouldn't call it a nightmare, but it really disturbed me. I had a dream about a good girlfriend of mine. We were at church together working on a project and in the dream I was very jealous of her for something. I actually am jealous of her for. Anyhow, I dreamed that after she left church she was hit by an oncoming truck and she died. I woke up really shocked and disturbed, thinking that I was wishing her dead because of the jealousy."

Sheridan put it in a different perspective.

"He told me that when someone dies in a dream, you're not necessarily wishing them dead. You have to look at the death in perspective -- what was happening in the rest of the dream? He explained that my dream was telling me to let the image die -- that image I had of her that I was comparing myself to.

"And I believed him. It really clicked with me and helped me with my jealousy of my girlfriend and in dealing with that dream."

Still, many sleep researchers believe that nightmare sufferers don't always have to rely on psychoanalysis to find relief.

"There is not good empirical scientific evidence," said Ann Germain, a sleep researcher at Western Psychiatric Institute in Oakland, "that it's necessary to interpret dreams and attach meaning and symbols to them in order for people to get better."

Some believe that a combination of psychotherapy and rehearsal therapy is the best answer.

"Nightmares are often the leading distressing symptom of very severe trauma, and [rehearsal therapy] can target it directly," said Alan Siegel, a San Francisco-based clinical psychologist. It "seems to dissipate the most distressing symptoms and opens the door for additional work."