Parasomnias are unpleasant or undesirable behaviours or experiences that occur predominantly during or within close proximity to sleep. Pharmacological treatments of parasomnias are available, but their efficacy is established only for few disorders. Furthermore, most of these disorders tend spontaneously to remit with development. Nonpharmacological treatments therefore represent valid therapeutic choices. This paper reviews behavioural and cognitive-behavioural managements employed for parasomnias. Referring to the ICSD-3 nosology we consider, respectively, NREM parasomnias, REM parasomnias, and other parasomnias. Although the efficacy of some of these treatments is proved, in other cases their clinical evidence cannot be provided because of the small size of the samples. Due to the rarity of some parasomnias, further multicentric researches are needed in order to offer a more complete account of behavioural and cognitive-behavioural treatments efficacy.
The term “parasomnia” is derived from the Greek “para” (meaning “alongside of”) and the Latin word “somnus” (meaning “sleep”). Parasomnias are defined as unpleasant or undesirable behaviours or experiences that occur predominantly during the sleep period or within close proximity to sleep. During the last century these phenomena have been carefully studied both polygraphically and clinically, showing that they encompass a wide number of conditions. According to the International Classification of Sleep Disorders (ICSD-3) parasomnias may be categorized according to the sleep phase of origin: Rapid Eye Movement (REM) sleep parasomnias, non-REM (NREM) sleep parasomnias, or miscellaneous, when they arise independently of sleep stage [
Since parasomnias are typically benign experiences that tend to resolve spontaneously in the course of development, they are frequently overlooked both by patients and clinicians. Consequently, few studies concern the treatment of these conditions, and most of these works are uncontrolled and based mostly on case reports.
Pharmacological treatments are available for these disorders, but the evidence of their efficacy is variable depending on the disorder. Furthermore, since most of NREM parasomnias are typical of childhood, particular attention must be paid towards pharmacological side effects. Consequently, behavioural and cognitive-behavioural treatments of sleep disorders received a growing attention in the last decades.
Despite the fact that the best known and validated cognitive and behavioural interventions aim to treat insomnia [
A systematic account of nonpharmacological treatments efficacy is lacking. This review will therefore cover the nonpharmacological treatments available for parasomnias, taking into account both controlled studies and case reports.
NREM parasomnias are classified on the basis of the behaviours displayed by the patient during the episode [
There are no large controlled trials assessing treatment efficacy in most of these conditions. Most of what is known comes from small trials or clinical and anecdotal evidence.
Confusional arousals (CA) are characterized by disoriented behaviour or slow mentation during an arousal from NREM sleep [
The first-line treatment in children with CA is reassurance, because the disorder tends to decline spontaneously with age [
Attarian suggests scheduled or anticipatory awakening as a behavioural technique to prevent these events [
When CA become frequent or do not respond to behavioural therapy, the possibility of a comorbid sleep disorder should be ruled out. Treating the concomitant conditions may reduce the episodes [
Sleep terrors (ST), also known as night terrors or pavor nocturnus, are conditions characterized by an unexpected arousal from stage N3, with an abrupt scream and behavioural manifestations of intense fear. They usually have a sudden onset, and the individual displays behaviours of extreme distress, confused verbalizations, autonomic arousal, and increased body movements, sometimes including sleepwalking. The child cannot be consoled or woken and typically has a partial or complete amnesia of the episodes the next day [
The first treatment in children with infrequent episodes of ST is reassurance, since they often outgrow it by late adolescence [
The patients should also be educated to avoid sleep deprivation and other precipitants, such as alcohol and drugs [
When the episodes become more frequent or tend to persist into adulthood, treatment is warranted. A wide range of drugs has been suggested, but potential side effects must be a cause for concern, especially in younger patients. Behavioural methods include psychotherapy [
Anticipatory or scheduled awakening can also be used to prevent ST [
Kellerman [
Kales et al. [
Hurwitz et al. [
Somnambulism, or Sleepwalking (SW), is a parasomnia characterized by complex purposeless tasks and wandering episodes of variable duration, arising from stage N2 or N3. Frequently the patients show no memory of the event [
Most cases of SW are benign and resolve spontaneously without treatment when the child grows up. Hence, the first-line treatment is supportive and includes avoiding sleep deprivation and creating a safe environment, giving the sleepwalker quiet guidance back to bed if necessary. It can be also noteworthy to reassure the patient that SW is not linked with underlying psychiatric illness. Treating other apparent predisposing factors and addressing triggering factors is also important. In particular, reversing comorbid sleep disordered breathing conditions often dramatically diminishes nocturnal behaviours, even when patients only have a mild burden of disease [
Nevertheless, if symptoms become chronic and the frequency of SW episodes is severe, a targeted intervention is indicated. A number of nonpharmacologic treatments, including anticipatory awakening, psychotherapy, and hypnotherapy have been reported.
Anticipatory awakenings are used in children with NREM parasomnias [
Behavioural interventions aimed to change the sleep pattern are also suggested: some authors hypothesized that daytime naps could decrease depth of night-time sleep and reduce the number of partial arousals [
Psychotherapy may be helpful for treating SW in adults. A case report of two patients showed that psychotherapy helped developing strategies to cope with the patient’s psychological conflicts [
The evidence for hypnotherapy is based mostly on anecdotal data and case reports. In two studies, a significant improvement after more than 6 months of followup was reported [
To our knowledge, randomized controlled trials of nonpharmacological treatments for somnambulism are lacking. Observational evaluations have generally been retrospective and uncontrolled and have relied solely on self-report of improvement by patients as outcome measures.
The ICSD-3 defines sleep-related eating disorder (SRED) as a NREM sleep parasomnia characterized by recurrent episodes of eating, occurring after sleep onset and accompanied by a reduced level of awareness. The sleep-related eating episodes are not linked to daytime eating disturbances such as bulimia nervosa, binge-eating disorder, or anorexia nervosa [
The distinction between SRED and Nocturnal Eating Syndrome (NES), which is openly recognized as an eating disorder, is still controversial. The main feature that distinguishes these two conditions is the level of awareness during the food intake, which is not impaired in NES [
In 1993, Schenck et al. [
Since an association between the usage of zolpidem and SRED has been suggested, a specific comprehensive assessment is requested before starting this therapy in patients with insomnia. In fact, zolpidem may cause or increase the frequency of SRED episodes in patients with sleep pathologies that lead to repeated arousals [
All the other behavioural therapies studied in scientific literature refer to NES [
As parasomnias are grouped by the sleep phase in which they occur, REM sleep parasomnias can be defined as unpleasant behaviours and experiences arising from REM sleep. Three main parasomnias of this subtype are recognized: nightmare disorder, recurrent isolated sleep paralysis, and REM sleep behaviour disorder (RBD) [
Nightmares are defined as disturbing mental experiences that are able to awake the sleeper from REM sleep. The experience generated internally by the dreamer seems real and vivid and can cause a wide range of negatively toned experiences like anxiety, fear, terror, anger, rage, and embarrassment that result in somatic manifestations like tachycardia, sweating, and tachypnoea. After the arousal, the subject is able to recover the content of the nightmare and is fully alert. The frequency of nightmares represents the disorder itself [
In children nightmares are very common, with a frequency of 75%, while in general population lifetime prevalence of nightmare experiences is close to 100% [
Although reported in strong relation with Posttraumatic Stress Disorder (PTSD), where the presence of nightmare follows a traumatic event, nightmares can occur also in other pathological conditions, such as drug abuse and stressful events and can be considered as normal reactions to acute and chronic combat and operational stress [
Since nightmares are defined by their qualitative and quantitative features (i.e., content and frequency), a detailed evaluation is fundamental, both from treatment and research. The assessment of nightmares is typically performed with specific questionnaires assessing the frequency, distress, and intensity of the episodes [
There are six behavioural and cognitive-behavioural techniques for the treatment of nightmares in the literature: imagery rehearsal therapy (IRT); exposure techniques; exposure, relaxation, and rescripting therapy (ERRT); lucid dreaming therapy (LDT); hypnosis; eye movement desensitization and reprocessing (EMDR).
In IRT the patient is asked to modify the plot of the recurring nightmare during wakefulness by verbal or written form, with a new self-made script in which the unpleasant part and/or the ending of the nightmare is replaced with a more pleasant one [
Exposure techniques consist in gradually exposing the patient to the source of the negative part of the nightmare during wakefulness and in safe surroundings [
In ERRT different types of intervention such as psychoeducation, sleep hygiene, progressive muscle relaxation, and rescripting the nightmare as exposure are combined together [
LDT is a restructuring cognitive technique. The patient is taught to become lucid in his nightmare through daily exercises. Consequently, he will be able to perform actions during the nightmare that will modify its storyline [
Hypnosis can be also adopted for the treatment of nightmares. Although the authors stated that the data were “very preliminary,” the treatment seemed to be effective [
According to the only meta-analysis investigating the size effect [
Also EMDR is employed for nightmares treatment. This is an 8-phase approach in which bilateral eye movement, tones, and taps are used to identify and reprocess the targeted disturbed memories and experiences in order to formulate insight and adaptive behaviour in patient with traumatic experiences. To our knowledge, the efficacy of this technique has been tested only in cohorts of PTSD patients [
At the moment it remains unclear whether nightmare disorder can equally benefit from all these different interventions, independently of the associated conditions (e.g., MD and PTSD).
Recurrent isolated sleep paralysis can be defined as the persistence of REM sleep, in terms of muscle atonia, into wakefulness. This condition is identified with an inability to speak and to move the limbs and the trunk at sleep onset or upon awakening from sleep, even though the subject maintains a conscious state and a proper recall of the situation. The duration of the episode may vary from seconds to minutes [
To our knowledge, no controlled studies of behavioural treatment for this condition are present in the literature. However, a reasonable management of this parasomnia is possible. Since sleep paralysis represents a benign and infrequent parasomnia, reassurance is the first-line treatment [
As the frequency of sleep paralysis can be increased by sleep deprivation, a correct sleep hygiene is highly recommended, especially for shift workers and in circadian disorder induced by jet lag [
REM sleep behaviour disorder (RBD) is a parasomnia characterized by the absence of sleep atonia during REM sleep and acting out of dreams, leading to injurious or potentially dangerous behaviours to the patients or bedmate [
RBD represents the only parasomnia for which the pharmacological intervention is the clear mainstay of the treatment. However, controlling environmental safety is a fundamental intervention. Hence, likely dangerous objects should be removed from the bedroom, windows protected, mattresses positioned on the floor, and cushions put around the bed. These interventions are even more important when drug intolerance or ineffectiveness develops [
According to ICSD-3, under the category “other parasomnias” are enlisted all parasomnias that are not related to a specific sleep stage [
Exploding head syndrome (EHS) is characterized by the perception of an abrupt, sudden, loud noise or sense of explosion in the head when going to sleep or waking up [
No controlled clinical trial is currently reported in the literature for this syndrome. A nonpharmacological treatment is anyway possible and may be effective. In different studies [
Sleep-related hallucinations are hallucinatory experiences, in particular visual phenomena, that occur at sleep onset (hypnagogic) or on awakening (hypnopompic) [
Being the least studied parasomnia, little is known about treatment possibilities. Different studies suggest that sleep deprivation, cigarette smoking, and certain medications such as
Sleep enuresis is characterized by the intermittent involuntary voiding during sleep, in absence of a physical disease, in children older than 5 years. Episodes can occur either during REM or NREM sleep [
A consistent literature about nonpharmacological treatment of nocturnal enuresis is present [
One of the most dated techniques is the alarm training, employed since 1938 [
Children with nocturnal enuresis have an increased risk of psychological and behavioural disorders. When marked symptoms are present, a full psychological or psychiatric assessment is recommended. The NICE guideline concludes that there is no evidence to justify the cost of psychotherapy for enuresis without clinically relevant psychological disorder. In this particular case, NICE recommends treating comorbid disorders, in order to improve the adherence to enuresis treatment [
Other complementary treatments (i.e., acupuncture) have been used for sleep enuresis. Among them hypnotherapy has been studied in one small randomized controlled trial, in which it appeared to be as effective as a pharmacological intervention (imipramine), with a lower relapse rate after cessation of treatment [
Several behavioural and cognitive-behavioural treatments of parasomnias are available. They have the obvious advantage of avoiding the risk of side effects of pharmacotherapy and deserve particular attention.
As this paper shows, the literature to date is based mainly on case reports or uncontrolled studies in small samples, offering only few examples of well-designed researches. Concerning sleepwalking, nightmares, and enuresis there is a number of controlled trials that allow evaluating the efficacy of these treatments. However, not all these studies of nonpharmacological treatments in sleepwalking were performed with adult patients, and the number of patients enrolled for the other studies was often limited. On the other hand, most of the behavioural and cognitive-behavioural treatments of other parasomnias cannot rely on valuable evidence.
Nonetheless, a nonpharmacologic approach to sleep disorders carries several further benefits. First of all, cognitive and behavioural treatment implies that the patient has an active part in his own treatment. This can possibly lead to a long term benefit to the patient if he learns how to recognize the signs of his disease and how to cope with it. Also, this can have a repercussion on the patient’s awareness and ultimately on his quality of life.
Because of the rarity of some parasomnias and the limits of the studies reviewed in this paper, larger multicentric trials would be required. This will help to further evaluate the efficacy of behavioural and cognitive-behavioural treatments of parasomnias in adults and to compare them to pharmacologic treatments.
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors would like to thank the anonymous reviewers for the useful comments.