Sleep state misperception (SSM), also known variously as paradoxical insomnia, pseudo-insomnia or subjective insomnia, refers to anyone who mistakenly perceives their sleep as wakefulness and thus severely underestimates their sleep time. It can also, less commonly, refer to the opposite misperception of overestimating sleep. While anyone may of course make such an error, sleep state misperception is considered a sleep disorder when such misperceptions become ingrained or chronic.
Sleepers with SSM will often report not having slept at all, or having slept very little, even though clinical recordings (e.g. using a polysomnograph or actigraph) may demonstrate normal or near normal sleep patterns. It may be diagnosed when a person – otherwise healthy, both psychiatrically and medically – is not really tired, despite their subjective perception of not having slept. Thus, this perception of poor sleep may be entirely illusory, and even their reports of excessive daytime sleepiness may be merely “nocebo” effects based on their own expectations.
SSM is essentially a type of hypochondria, and there are no real symptoms to treat, so treatment usually involves treatment of the underlying depression or anxiety. Sedatives may be prescribed to help relieve the symptoms, although this may lead to undesirable complications such as drug dependency, and often education about normal sleep patterns may be enough to alleviate the anxiety.