07. November 2019
Most people are familiar with sleep disorders – probably everyone has tossed and turned at night and not found sleep. In addition to rather harmless causes, such as short-term stress or colds, psychological disorders can also trigger sleep disorders. Post-traumatic stress disorder (PTSD) also causes sleep problems. However, the relationship between sleep and PTSD here is more complex than thought: disturbed sleep is not only a consequence of PTSD, but can also contribute to it.
Below, we review the different stages of sleep, the relationship between PTSD and sleep quality, and new treatment approaches for PTSD.
Sleep is not always the same. In the course of a night, we sleep through several sleep cycles composed of different phases. These phases differ by a change in brain and body activity. To find out which sleep phase we are in, sleep researchers can measure brain waves with an EEG (electroencephalogram) and use other sensors to record motor activity and eye movements under closed eyelids. Sleep is divided into two forms, REM sleep and non-REM sleep. REM means “Rapid-Eye-Movement”, mostly intense dreaming takes place during REM sleep.
In one night, we go through different sleep stages that repeat several times. Most often, the stages proceed in a 60-90 minute cycle. During eight hours of sleep, we go through approximately 4 to 7 sleep cycles. In PTSD, the sleep stages shift: Less REM sleep takes place. This has an influence on the psychological processing of the traumatic content.
The body finds relaxation: pulse and breathing become calmer, muscle tension decreases. Initially, the EEG here still shows high similarity to the waking state, then sleep-typical brain waves appear more frequently. The eyes make rolling movements behind the closed eyelids. If we are not awakened by unfamiliar sounds or other stimuli, we find our way to sleep.
We spend most of the night in this phase. Muscle tension continues to subside, and breathing is deep and relaxed. No eye movements can be detected. The EEG shows a typical pattern, the so-called “sleep spindles”, which occur in a certain rhythm.
In deep sleep, regeneration takes place, the immune system is strengthened and learning experiences are internalized. If one is awakened from deep sleep, it is particularly unpleasant and getting up is difficult. There is no eye movement here either. We spend about 20% of the night in deep sleep.
REM sleep (rapid eye movement sleep)
The name results from the jerky and rapid eye movements behind the closed eyelids. In REM- sleep, we dream intensely. There are rapid eye movements with closed eyelids and increased breathing and heart rate. Despite the active sleep state, we do not move at all during this phase. This rigidity prevents us from hurting ourselves in dreams. As we age, REM sleep changes. In adults, the REM sleep phase lasts more than an hour. Babies, on the other hand, spend almost all of their sleep exclusively in REM sleep. Researchers conclude that REM sleep plays a crucial role in the development of the nervous system and in the processing of learning content. In the EEG, REM sleep is more like the falling asleep phase, so the brain is quite active.
After severely stressful events, many people suffer from sleep problems. In PTSD, the natural sleep rhythm and the sequence of sleep phases are disturbed. In this context, the deep sleep and REM phases are of high importance, because learning and memory content is processed and stored in them. If the phases fall away, the processing is incomplete. Let’s take a closer look at the connections between sleep and PTSD:
Connection 1: Interplay between sleep and PTSD
After a traumatic event, sleep is understandably impaired. The memory is still so painful that restful sleep is unthinkable. The problem: During sleep, all experiences, including traumatic content, are stored and processed. If this does not happen, because there is no REM or deep sleep phases, then the traumatic episode is processed only fragmentarily, which leads to the already above-mentioned incomplete memory (partial amnesia). This entails further problems, e.g., affected persons feel alienated from themselves and experience flashbacks in situations that they do not associate with the traumatization.
Connection 2: Poor sleep as a consequence of PTSD
PTSD-afflicted individuals suffer from increased irritability, anxiety, and depressed moods. All of these symptoms are not very conducive to healthy sleep, so the quality of sleep suffers further.
Result: vicious circle
From the two described connections, results in a vicious circle, in which the PTSD and the sleep disorder maintain each other. The scientists were able to prove it with an experiment. In this experiment, test subjects who actually have no sleep problems watched either a neutral or a traumatic film. It turned out that the subjects who watched the traumatic film had fewer REM phases during sleep than the subjects who watched the neutral film. However, there were also differences in the trauma group itself: the longer the REM – sleep was (even though it was still shortened compared to the individuals in the neutral group), the fewer trauma-related symptoms the participants exhibited (Sopp et al., 2019).
For the resolution of sleep problems, sleep and sleep hygiene should first be given great importance in therapy. Sleep hygiene includes measures that should support healthy sleep, such as the introduction of sleep rituals or relaxation procedures before the night.
On the other hand, the links between sleep and PTSD influence the choice of therapeutic methods: In the EMDR method (Eye Movement Desensitization and Reprocessing), the typical characteristics of the REM phase are exploited and trauma management is supported by the combination of linguistic reexperiencing and rapid eye movements.
The effectiveness of classical confrontation therapy with traumatic content and stimuli can also be improved by incorporating the findings: If the proportion of REM sleep phases is increased, the events are better processed and the confrontation has a faster effect.
In this area, despite the existing knowledge, there is still a great need for research and an enormous potential in the treatment of PTSD. We can be curious about what findings science will provide us with in the future and can hope for a constantly improving, scientifically supported therapy for PTSD!