Insomnia is a relatively common sleep disorder affecting approximately 10-25% of adults and is defined as a subjective complaint of “dissatisfaction with sleep quality and quantity despite adequate opportunity for sleep” (International Classification of Sleep Disorders 3rd edition and Diagnostic and Statistical Manual of Mental Disorders 5th edition). These sleep disturbances are often associated with daytime symptoms such as fatigue, impairment in work-related performance, and poor quality of life. It is also associated with various comorbidities including depression, anxiety, substance abuse, dementia, and cardiovascular disease.
Typically, patients with chronic insomnia will demonstrate objective differences in sleep quantity and/or quality (e.g., increased sleep onset latency and/or reduced total sleep time) compared to those without insomnia, as confirmed via polysomnography testing. However, in some cases, there may be no clear objective evidence to corroborate the subjective complaints in sleep disturbance. This mismatch between subjective and objective sleep measures is referred to as paradoxical insomnia and is thought to be due to a tendency by these patients to underestimate their total amount of sleep. It is thought that anywhere from 14-62% of patients with chronic insomnia experience paradoxical insomnia; however, accurate estimation for the prevalence of paradoxical insomnia is particularly difficult due to a lack of standardized quantitative criteria for diagnosis.
Paradoxical insomnia is currently recognized as a subtype of insomnia by the International Classification of Sleep Disorders 3rd edition. Despite this however, there is still much debate amongst sleep physicians as to whether paradoxical insomnia is a true condition separate from classical insomnia or if sleep state misperception is simply a trait of classical insomnia, with some extreme cases showing greater levels of misperception. Regardless of whether paradoxical insomnia is a “real” condition, better understanding and reporting of subjective vs. objective sleep misperception would still be useful in the diagnosis and management of chronic insomnia.
Sources
Haslam et al., (2025) Paradoxical Insomnia Versus Atypical Obstructive Sleep Apnea or Mixed Disorder? Case Report and Literature Review. Clin Case Rep. 13(9):e70883. DOI: https://doi.org/10.1002/ccr3.70883
Castelnovo et al., (2019). The paradox of paradoxical insomnia: A theoretical review towards a unifying evidence-based definition. Sleep Medicine Reviews. 44: 70-82. DOI: https://doi.org/10.1016/j.smrv.2018.12.007
Rezaie et al., (2018). Paradoxical insomnia and subjective-objective sleep discrepancy: a review. Sleep Medicine Reviews. 40: 196-202. DOI: https://doi.org/10.1016/j.smrv.2018.01.002
