Acting Out Dreams Predicts Later Dementia

REM Behavior Disorder Strongly Linked to Other Brain Disorders

It sounds too strange to be true, but it is actually possible for people to begin to act their dreams out. This can manifest in bizarre and astonishing ways. Though typically episodic, when dream enactment occurs it can cause serious harm to the afflicted person or a bed partner. These behaviors are most commonly associated with REM behavior disorder (RBD). Interestingly, these unusual episodes may predict the later development of other neurodegenerative conditions such as dementia and even Parkinson’s disease. Learn about the relationship between acting out dreams and the incidence of these subsequent neurodegenerative conditions.

Woman sleeping in bed near open window
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What Is REM Behavior Disorder?

REM behavior disorder is a parasomnia that is associated with sleep behaviors that occur out of REM sleep. In this state, the muscles are usually paralyzed so that dream enactment cannot occur. In some individuals, it becomes possible to act out the content of dreams as muscles are no longer adequately relaxed in REM. This is usually achieved at the level of the brainstem, but changes may lead to a failure to interrupt the signals between the sleeping brain and body. Those afflicted are typically older than age 50 and are more commonly men.

The resulting behaviors are often violent and can include hitting, kicking, jumping out of bed, and other actions. There may be vocalizations such as laughing, talking, or yelling. The movements are often associated with an associated dream and the content can be recalled promptly upon awakening. These dreams are often action-packed and may involve fighting off an attacker. The precise content varies widely but the recalled dream corresponds closely with the observed action.

The Development of Other Degenerative Conditions

The behaviors associated with RBD can occur decades prior to the onset of other neurodegenerative changes. In fact, it seems that the majority of those afflicted with RBD will go on to develop other conditions. In particular, Parkinson’s disease, Lewy body dementia, and multiple system atrophy seem to be associated with RBD. It may take years — sometimes even decades — before these other conditions develop. In some individuals, the other disorders may never fully manifest as death occurs due to other causes.

Though not all go on to develop the other associated conditions, it occurs with a high frequency. More than 80% (70%)of people with RBD go on to develop Parkinson’s symptoms, for example. Though also commonly seen early in the other two conditions, far fewer will go on to develop these disorders.

It is important to obtain an accurate diagnosis of the behaviors. Other parasomnias may also manifest with movements during sleep. Certain medications, including antidepressants and anticholinergics, may provoke sleep behaviors. In addition, there are other medical disorders such as multiple sclerosis, narcolepsy, and stroke that might result in RBD.

The Hope of REM Behavior Disorder

There is also a silver lining to the association between RBD and these other conditions. It may allow for research to prevent the later development of the related neurodegenerative disorders. In the future, early interventions may help to forestall the other diseases.

In the meanwhile, it is important to take appropriate safety precautions to prevent harm when the behaviors begin. There are also effective treatments, including the use of higher doses of melatonin and the prescription medication called clonazepam.

If you experience behaviors out of sleep associated with dream content, seek further evaluation by a sleep specialist and get the diagnosis and treatment that you need. Long-term neurological follow-up may allow prompt intervention to treat other symptoms and may one day allow therapy to reduce the likelihood of developing the other associated disorders.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading
  • American Academy of Sleep Medicine. International classification of sleep disorders, 3rd ed. Darien, IL: American Academy of Sleep Medicine, 2014.

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.