Parasomnias are a group of disruptive sleep problems most commonly seen in children but possible at any stage of life, which can result in undesirable physical or verbal behaviours. Common parasomnias include sleep walking, sleep talking, sleep terrors, nightmares, and REM sleep behaviour disorder (RBD).

Overview—What Are Parasomnias?

RBD involves talking, moving vigorously, or even calling out during sleep—particularly during REM sleep with vivid dreams. RBD can be dangerous to sufferers and partners due to sudden movements and possible defense against perceived attack.

Nightmares are frightening, vivid dreams that tend to interrupt sleep, and stop people easily returning to sleep. Some nightmares can repeat through the course of a person’s life (idiopathic nightmares) and some may be linked to trauma (these tend to have vivid images linked to traumatising events).

Sleepwalking involves people moving about while in deep sleep—sometimes getting out of bed, walking around, or even leaving the house. Sleepwalking is very rarely remembered, can vary greatly in frequency between people, and usually starts in childhood and becomes less frequent over time.

What Causes Parasomnias?

RBD involves the brain sending the wrong signals to the body muscles during REM sleep, so that the muscles fail to relax—this causes movement during dreams. The first type of RBD occurs in people over 50 years old and affects mostly men—and its cause is unknown. The second form of RBD happens as a side effect of medicines, including high doses of some antidepressants.

Nightmares tend to happen during the REM or dream stage of sleep. Children tend to experience dreams and nightmares more intensely, often have more vivid imaginations, and sometimes therefore experience fear or confusion. Less common in adults, nightmares can be caused by stress, trauma, mental illness (e.g. schizophrenia), or various illnesses and medicines, particularly some of the commonly used blood pressure medications.

Sleepwalking is thought to be inherited in some people, and also part of a natural stage of development for children. Around 75% of all adults report having sleepwalked at least once in their lives. Whatever the stage of life, sleepwalking, may be triggered or return during periods of high stress and sleep deprivation.

How are Parasomnias Assessed & Treated?

RBD is usually assessed overnight in a sleep study, after the possibility of being caused by medication or anything else obvious is ruled out. Treatment depends on the exact cause, but can include medication or treatment of Obstructive Sleep Apnoea.

Nightmares in children tend to lessen in frequency and intensity naturally over time, so simply reassuring children is all that is required. In adults, treatment may include learning methods that develop the capacity to change the storyline of the nightmare and other specialised strategies. Some medicines are used to reduce the intensity of nightmares, and are effective for trauma-related and other types of nightmares. Many patients benefit from seeing a Sleep Psychologist to help with their nightmares.

Sleepwalking in children usually resolves itself as the children grow up, and parents are advised to simply comfort children after any sleepwalking, and only seek help if the sleepwalking is affecting wellbeing through daytime tiredness or risk of injury. In adults the adoption of better sleep habits is important to treat sleepwalking, and medication may be prescribed in some cases, particularly for people who sleepwalk on a regular basis.