390 Sleep-Wake Disorders
most relevant to the mental he alth provider, with medication use (e.g., benzodiazepines, opi-
ates). Congenital central alveol ar hypoventilation often occurs in association with autonomic
dysfunction and may occur in association with Hirschsprung’s disease. COPD, a disorder of
lower airway obstruction usually associated with cigarette sm oking, can result in sleep-
related hypoventilation and hypoxemia. The pres ence of coexisting obstructive sleep apnea
hypopnea is thought to exacerbate hypoxemia and hypercapnia during sleep and wakeful-
ness. The relationship between congenital central alveolar hypoventilation and idiopathic
sleep-related hypoventilation is unclear; in some individuals, idiopathic sleep-related hy-
poventilation may represent cases of late-onset  congenital central alveolar hypoventilation.
Relationship to Internat ional Classification of 
Sleep Disorders
The International Classificat ion of Sleep Disorders,  2nd Edition (ICSD-2), combines sleep-
related hypoventilation and sleep-related hypo xemia under the category of sleep-related
hypoventilation/hypoxemic syndromes. This ap proach to classificati on reflects the fre-
quent co-occurrence of disorder s that lead to hypoventilation  and hypoxemia. In contrast,
the classification used in DS M-5 reflects evidence that th ere are distinct sleep-related
pathogenetic processes le ading to hypoventilation.
Circadian Rhythm Sleep-Wake Disorders
Diagnostic Criteria
A. A persistent or recurrent pattern of sleep disruption that is primarily due to an alteration
of the circadian system or to a misalignment between the endogenous circadian
rhythm and the sleep–wake schedule required by an individual’s physical environment