Sleep state misperception

Sleep state misperception (SSM) is a term in the International Classification of Sleep Disorders (ICSD) most commonly used for people who mistakenly perceive their sleep as wakefulness,^[1][2] though it has been proposed that it be applied to those who severely overestimate their sleep time as well^[3] ("positive" sleep state misperception).^[4] While most sleepers with this condition will report not having slept in the previous night at all or having slept very little,^[5] 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).^[6]

Patients are otherwise generally in good health,^[1] 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.^[7]

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."^[1]

The validity and reliability of sleep state misperception as a pertinent diagnosis has been questioned,^[8] with studies finding poor empirical support.^[9]