There are many distinct sleep disorders, but most are characterized by one of the following symptoms: “excessive daytime sleepiness, difficulty initiating or maintaining sleep, or abnormal movements, behaviors, and sensations occurring during sleep.”127
There are currently three systems used to classify sleep disorders:
1. The Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition (commonly known as the DSM-V), published by the American Psychiatric Association, Washington, DC, 2013.128
This system lists 10 “sleep-wake disorders,” conditions (or groups of conditions) that are manifested by disturbed sleep that cause both distressed and impaired functioning during the daytime:
1. Insomnia disorder
2. Hypersomnolence disorder
4. Breathing-related sleep disorders, including:
o Obstructive sleep apnea hypopnea
o Central sleep apnea
o Sleep-related hypoventilation
5. Circadian rhythm sleep disorders, including:
o Advanced sleep phase syndrome
o Irregular sleep-wake type
o Non-24-hour sleep-wake type
6. Non-REM (NREM) sleep arousal disorders
7. Nightmare disorder
8. REM sleep behavior disorder
9. Restless legs syndrome
10. Substance- or medication-induced sleep disorder.
2. The International Classification of Sleep Disorders, Third Edition (ICSD-3), published by the American Academy of Sleep Medicine in 2014.129
ICSD-3 is published in association with the European Sleep Research Society, the Japanese Society of Sleep Research, and the Latin American Sleep Society. It distinguishes six subcategories of sleep disorders:
2. Sleep Related Breathing Disorders
3. Central Disorders of Hypersomnolence
4. Circadian Rhythm Sleep-Wake Disorders
3. The International Classification of Diseases, 10th edition (ICD-10), published by the World Health Organization, Geneva, Switzerland, 1994.130
The ICD-10 system sets aside two areas for sleep disorders: organic (ICD-10 code: G47) and nonorganic (ICD-10 code: F51), but it only includes a few actual sleep disorder diagnoses.
127. Institute of Medicine (IOM) Committee on Sleep Medicine and Research, Colten HR and Altevogt BM (ed.), Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem, Washington, DC: National Academy of Sciences, 2006.
128. American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Washington, DC: American Psychiatric Association, 2013. See also APA, Sleep-Wake Disorders Fact Sheet, Washington, DC, APA, 2013. On-line at: http://www.dsm5.org/Documents/Sleep-wake%20Disorders%20Fact%20Sheet.pdf
129. American Academy of Sleep Medicine, International Classification of Sleep Disorders, Third Edition: Diagnostic and Coding Manual, : American Academy of Sleep Medicine; 2014.
130. World Health Organization (WHO), International Classification of Diseases. 10th ed. Geneva, Switzerland: WHO; 1994.