606 Neurocognitive Disorders
Specify: 
Without behavioral disturbance:  If the cognitive disturbance is not accompanied by
any clinically significant behavioral disturbance.
With behavioral disturbance  (specify disturbance): If the cognitive disturbance is ac-
companied by a clinically significant behavioral disturbance (e.g., psychotic symptoms,
mood disturbance, agitation, apathy, or other behavioral symptoms).
Subtypes
Major and mild neurocognitive disorders (NCD s) are primarily subtyped according to the
known or presumed etiological/pa thological entity or entities  underlying the cognitive de-
cline. These subtypes are distin guished on the basis of a combin ation of time course, charac-
teristic domains affected, and associated sy mptoms. For certain etio logical subtypes, the
diagnosis depends substantially on the presence of a potentially causative entity, such as Par-
kinson’s or Huntington’s disease, or a traumati c brain injury or stroke in the appropriate time
period. For other etiological subt ypes (generally the neurodegenerative diseases like Alzhei-
mer’s disease, frontotemporal lobar degenerati on, and Lewy body disease), the diagnosis is
based primarily on the cognitive, behavioral, an d functional symptoms. Typically, the differ-
entiation among these syndromes that lack an independently recognized etiological entity is
clearer at the level of major NCD than at the level of mild NCD, but sometimes characteristic
symptoms and associated features are present at the mild level as well. 
NCDs are frequently managed by clinicians  in multiple disciplines. For many sub-
types, multidisciplinary international expert groups have developed specialized consen-
sus criteria based on clinicopathological corr elation with underlying brain pathology. The
subtype criteria here have been harm onized with those expert criteria.
Specifiers