Sleep state misperception (SSM) is a term in the

International Classification of Sleep Disorders The International Classification of Sleep Disorders (ICSD) is "a primary diagnostic, epidemiological and coding resource for clinicians and researchers in the field of sleep and sleep medicine". The ICSD was produced by the American Academy of Slee ...

(ICSD) most commonly used for people who mistakenly perceive their

sleep Sleep is a sedentary state of mind and body. It is characterized by altered consciousness, relatively inhibited Perception, sensory activity, reduced muscle activity and reduced interactions with surroundings. It is distinguished from wakefuln ...

as wakefulness,Minecan, Daniela, and Antonio Culebras. http://www.medlink.com/web_content/MLT0003S.asp "Sleep state misperception." ''MedLink Neurology''. Originally published: September 6, 1995. Updated: October 29, 2008.'' though it has been proposed that it be applied to those who severely overestimate their sleep time as wellKushida, Clete A.
Handbook of Sleep Disorders
'' Informa Health Care, 2008. , . (Page 32) ("positive" sleep state misperception). While most sleepers with this condition will report not having slept in the previous night at all or having slept very little,Insomnia Causes
Healthcommunities.com. Original Publication: 01 Dec 2000. Updated: 01 Dec 2007. clinical recordings generally show normal sleep patterns. Though the sleep patterns found in those with SSM have long been considered indistinguishable from those without, some preliminary research suggest there may be subtle differences (see Symptoms and diagnosis: Spectral analysis). Patients are otherwise generally in good health, and any illnesses—such as depression—appear to be more associated with fear of negative consequences of insomnia ("insomnia phobia") than from any actual loss of sleep. Sleep state misperception was adopted by the ICSD to replace two previous diagnostic terminologies: "subjective insomnia complaint without objective findings" and "subjective sleepiness complaint without objective findings." The validity and reliability of sleep state misperception as a pertinent diagnosis has been questioned, with studies finding poor empirical support.

Classification

Sleep state misperception is classified as an intrinsic

dyssomnia Dyssomnias are a broad classification of sleeping disorders involving difficulty getting to sleep, remaining asleep, or of excessive sleepiness. Dyssomnias are primary disorders of initiating or maintaining sleep or of excessive sleepiness and ar ...

. While SSM is regarded a sub-type of

insomnia Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...

, it is also established as a separate sleep-condition, with distinct

pathophysiology Pathophysiology ( physiopathology) – a convergence of pathology with physiology – is the study of the disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Pathology is ...

. Nonetheless, the value of distinguishing this type of insomnia from other types is debatable due to the relatively low frequency of SSM being reported. Sleep state misperception can also be further broken down into several types, by patients who: * report short sleep (subjective insomnia complaint without objective findings) ** or no sleep at all (subjective ''total'' insomnia) * report

excessive daytime sleepiness Excessive daytime sleepiness (EDS) is characterized by persistent sleepiness and often a general lack of energy, even during the day after apparently adequate or even prolonged nighttime sleep. EDS can be considered as a broad condition encompass ...

(subjective sleepiness complaint without objective findings) * report sleeping too much (subjective

hypersomnia Hypersomnia is a neurological disorder of excessive time spent sleeping or excessive sleepiness. It can have many possible causes (such as seasonal affective disorder) and can cause distress and problems with functioning. In the fifth edition ...

without objective findings)

Validity

The validity and reliability of the sleep state misperception as a pertinent medical entity was questioned. A study found poor empirical support for this diagnostic item.

Symptoms and diagnosis

This

sleep disorder A sleep disorder, or somnipathy, is a medical disorder of an individual's sleep patterns. Some sleep disorders are severe enough to interfere with normal physical, mental, social and emotional functioning. Polysomnography and actigraphy are tests ...

frequently applies when patients report not feeling tired despite their subjective

perception Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous syste ...

of not having slept. Generally, they may describe experiencing several years of no sleep, short sleep, or non-restorative sleep. Otherwise, patients appear healthy, both psychiatrically and medically. (That this condition is often

asymptomatic In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered a ...

could explain why it is relatively unreported.) However, upon clinical observation, it is found that patients may severely overestimate the time they took to fall asleep—often reporting having slept half the amount of time indicated by

polysomnogram Polysomnography (PSG), a type of sleep study, is a multi-parameter study of sleep and a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG. The name is derived from Greek and Latin roots: the Gree ...

electroencephalography Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocorte ...

(EEG), which may record normal sleep. Observing such discrepancy between subjective and objective reports, clinicians may conclude that the perception of poor sleep is primarily

illusion An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people. Illusions may oc ...

ary. Alternatively, some people may report

or chronic disabling sleepiness, while no sleep disorder has been found to exist. Methods of diagnosing sleepiness objectively, such as the Multiple Sleep Latency Test, do not confirm the symptomobjective sleepiness is not observed despite the complaint. Finally, on the opposite end of the spectrum, other patients may report feeling that they have slept much longer than is observed. It has been proposed that this experience be subclassified under sleep state misperception as "positive sleep state misperception", "reverse sleep state misperception", and "negative sleep state misperception".

Diagnostic criteria

The patient has a complaint of insomnia while sleep quality and duration are normal. Polysomnographic monitoring demonstrates normal sleep latency, a normal number of arousals and awakenings, and normal sleep duration with or without a multiple sleep latency test that demonstrates a mean sleep latency of greater than 10 minutes. No medical or mental disorder produces the complaint. Other sleep disorders producing insomnia are not present to a degree that would explain the patient’s complaint.

Detection and difficulties

Detecting sleep state misperception by objective means has been elusive. A 2011 study published in the journal Psychosomatic Medicine has shown that sleep misperception (i.e., underestimation of sleep duration) is prevalent among chronic insomniacs who sleep objectively more than 6 hours in the sleep lab. The psychological profile of these chronic insomniacs with objective normal sleep duration is characterized by depressive, anxious-ruminative traits and poor coping resources. Thus, it appears that not all chronic insomniacs underestimate their sleep duration, and that sleep misperception is a clinical characteristic of chronic insomniacs with objective normal sleep duration. Furthermore, rumination and poor coping resources may play a significant role in sleep misperception.

Spectral analysis

According to a May 2014 article published in ''

New Scientist ''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publish ...

'', spectral analysis may help clinicians find objective evidence for sleep state misperception:

Distinction from insomnia

What is considered objective

, unlike SSM, can easily be confirmed

empirical Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and ...

ly through clinical testing, such as by polysomnogram. Those who experience SSM may believe that they have not slept for extended periods of time, when they in fact do sleep but without perceiving it. For example, while patients who claim little or no sleep may usually acknowledge impaired job performance and daytime drowsiness, sleep state misperceivers often do not. Cases of objective total insomnia are extremely rare. The few that have been recorded have predominantly been ascribed to a rare incurable genetic disorder called

fatal familial insomnia Fatal insomnia is an extremely rare genetic (and even more rarely, sporadic) disorder that results in trouble sleeping as its hallmark symptom. The problems with sleeping typically start out gradually and worsen over time. Eventually, the patien ...

, which patients rarely survive for more than 26 months after the onset of illness—often much less.

Treatment

Behavioral treatment can be effective in some cases.

Sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but ...

hypnotics may also help relieve the symptoms.Hauri PJ. "Primary insomnia." ''Principles and practice of sleep medicine.'' 2nd ed. Philadelphia: WB Saunders, 1994. Additionally, education about normal patterns of the sleep-wake cycle may alleviate

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

in some patients. For patients with severe depression resulting from the fear of having insomnia,

electroconvulsive therapy Electroconvulsive therapy (ECT) is a psychiatric treatment where a generalized seizure (without muscular convulsions) is electrically induced to manage refractory mental disorders.Rudorfer, MV, Henry, ME, Sackeim, HA (2003)"Electroconvulsive th ...

appears to be a safe and effective treatment.

Complications

A subject who is not being monitored (by a recording or other observer) may not have a way to tell if a treatment is working properly due to the

amnesic Amnesia is a deficit in memory caused by brain damage or disease,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be caused temporarily by the use ...

nature of SSM. The condition may worsen as a result of persistent attempts to treat the symptoms through conventional methods of dealing with insomnia. The prescription of

hypnotic Hypnotic (from Greek ''Hypnos'', sleep), or soporific drugs, commonly known as sleeping pills, are a class of (and umbrella term for) psychoactive drugs whose primary function is to induce sleep (or surgical anesthesiaWhen used in anesthesia ...

s or

stimulant Stimulants (also often referred to as psychostimulants or colloquially as uppers) is an overarching term that covers many drugs including those that increase activity of the central nervous system and the body, drugs that are pleasurable and inv ...

s may lead to

drug dependency Substance dependence, also known as drug dependence, is a biopsychological situation whereby an individual's functionality is dependent on the necessitated re-consumption of a psychoactive substance because of an adaptive state that has develope ...

as a complication. Nonetheless, chronic SSM may increase risk for depression, anxiety, and

substance abuse Substance abuse, also known as drug abuse, is the use of a drug in amounts or by methods which are harmful to the individual or others. It is a form of substance-related disorder. Differing definitions of drug abuse are used in public health, ...

. It has also been noted that patients with this condition may sometimes opt to take medications over other treatments "for the wrong reasons (e.g. because of euphoriant properties)."

Epidemiology

SSM is poorly understood. As of 2008, there is little to no information regarding

risk factor In epidemiology, a risk factor or determinant is a variable associated with an increased risk of disease or infection. Due to a lack of harmonization across disciplines, determinant, in its more widely accepted scientific meaning, is often u ...

s or prevention, though it is believed to be most prevalent among young to middle aged adults. Distribution among the general population and by gender is unknown. About 5% of the clinical population may be affected, though that figure is subject to

sampling bias In statistics, sampling bias is a bias in which a sample is collected in such a way that some members of the intended population have a lower or higher sampling probability than others. It results in a biased sample of a population (or non-human f ...

References

External links

{{DEFAULTSORT:Sleep State Misperception Sleep physiology Sleep disorders Dream