Functional Consequences of 
Non-REM Sleep Arousal Disorders
For the diagnosis of a NREM sl eep arousal disorder to be ma de, the individual or house-
hold members must experience clinically signi ficant distress or impairment, although pa-
rasomnia symptoms may occur occasionally in nonclinical populations and would be
subthreshold for the diagnosis. Embarrassment concerning the episodes can impair social
relationships. Social isolation or occupational difficulties ca n result. The determination of a
“disorder” depends on a number  of factors, which may vary on an individual basis and
will depend on the frequency of  events, potential for violence  or injurious behaviors, em-
barrassment, or disruption/distr ess of other household member s. Severity determination
is best made based on the nature or consequenc e of the behaviors rather  than simply on fre-
quency. Uncommonly, NREM sleep arousal disorders may result in serious injury to the
individual or to someone trying  to console the individual. Inju ries to others are confined to
those in close proximity; individuals are not “sought out.” Typically, sleepwalking in both
children and adults is not associated with si gnificant mental disorders. For individuals
with sleep-related eating behaviors, unknowingly preparing or eati ng food during the
sleep period may create problems  such as poor diabetes control, weight gain, injury (cuts
and burns), or consequences of  eating dangerous or toxic in edibles. NREM sleep arousal
disorders may rarely result in violent or injurious behaviors with forensic implications.
Differential Diagnosis
Nightmare disorder. In contrast to individuals with NREM sleep arousal disorders, in-
dividuals with nightmar e disorder typically awaken eas ily and completely, report vivid
storylike dreams accompanying the episodes, and tend to have episodes later in the night.