PTSD May Be Less Severe Because of Dream Sleep

For years people have wondered about the purpose behind our dreams. What do dreams mean or do they mean anything at all? Do they serve any purpose? Scientists are gathering evidence which shows that at least one function dreams may serve is to soothe our painful memories. Without this soothing effect, horrifying memories filled with painful emotional barbs can consume a person, as is the case for those who suffer with Post Traumatic Stress Disorder (PTSD).

A team of researchers at the University of California, Berkeley hypothesized that dreams work to remove the fierce emotions attached to painful memories. They theorized that during the dream stage of sleep (Rapid Eye Movement or REM state), the brain experiences chemical changes which reduce the levels of certain stress hormones.

While the brain is in a calmed state, it is able to consider experiences and events and file them away into memory – minus the strong emotions attached to those events. Later on, when the person is awake and recalls the event, they are able to remember the occurrence without the intense pain once associated with the experience. That was the theory.

To test their theory the team recruited 35 volunteers in good health. The volunteers agreed to recline in a brain scanner as 150 images were flashed before their eyes. Some of the images were tame while others were extremely disconcerting, even jarring.

For example, one image of a nondescript tea kettle could be followed by a disturbing picture of the aftermath of a vehicular accident. As the volunteers viewed the images, they were asked to assign a numerical rating to the degree of emotional intensity associated with the picture. Half of the volunteers viewed images in the morning while the other half viewed them just prior to going to bed.

After 12 hours, when half of the volunteers had experienced sleep, they were asked to view images again. During the second viewing, the volunteers who had slept were found to rate even horrifying images as less emotionally intense. In addition, brain scanning revealed less activity in the region responsible for processing emotions.

During REM the chemical norepinephrine, which affects stress, appears to shut down. Doctors say that healthy sleep is that in which 20 percent of sleep time is given over to REM or dream stage. Thus the team’s theory that dreams act to remove some of the emotional sting from memories appears to be correct.

Studies show that for those suffering with PTSD, even periods of dreaming are charged with stress. When war veterans diagnosed with PTSD have been given medications which act to quiet the neurotransmitter responsible for maintaining such an excited state, the soldier’s sleep and dream stage improves and symptoms begin to abate.

Studies so far show that a simple blood pressure medication works to suppress norepinephrine activity in the brain, thereby enhancing the REM stage and minimizing the nightmares so often associated with the disorder.