361Sleep-Wake
 Disorders
The DSM-5 classification  of sleep-wake disorders is intended for use by general
mental health and medical clinicians (those caring for adult, geriatric, and pediatric pa-
tients). Sleep-wake disorders encompass 10 d isorders or disorder groups: insomnia disor-
der, hypersomnolence disorder, narcolepsy, br eathing-related sleep disorders, circadian
rhythm sleep-wake disorders,  non–rapid eye movement (NRE M) sleep arousal disorders,
nightmare disorder, rapid eye movement (REM) sleep behavior disorder, restless legs syn-
drome, and substance/medication-induced sleep disorder. Individuals with these disor-
ders typically present with sleep-wake complain ts of dissatisfaction regarding the quality,
timing, and amount of sleep. Resulting dayt ime distress and impairme nt are core features
shared by all of these sleep-wake disorders.
The organization of this chapter is designed to  facilitate differential diagnosis of sleep-
wake complaints and to clarify when referral to a sleep specialist is appropriate for further
assessment and treatment planning. The DSM-5 sleep disorders nosology uses a simple,
clinically useful approach, while also reflecti ng scientific advances  in epidemiology, ge-
netics, pathophysiology, assessment, and in terventions research since DSM-IV. In some
cases (e.g., insomnia disorder ), a “lumping” approach has been adopted, whereas in oth-
ers (e.g., narcolepsy), a “spli tting” approach has been taken, reflecting the availability of
validators derived from epidem iological, neurobiological, and interventions research. 
Sleep disorders are often accompanied by de pression, anxiety, an d cognitive changes
that must be addressed in treatment planni ng and management. Fu rthermore, persistent