Alzheimer's disease (pp. 611—614)
Frontotemporal lobar degeneration (pp. 614—618)
Lewy body disease (pp. 618—621)
Vascular disease (pp. 621—624)
Traumatic brain injury (pp. 624—627)
Substance/medication use (pp. 627—632)
HIV infection (pp. 632—634)
Prion disease (pp. 634—636)
Parkinson’s disease (pp. 636—638)
Huntington’s disease (pp. 638-641)
Another medical condition (pp. 641—642)
Multiple etiologies (pp. 642—643)
Unspecified (p. 643)
Coding note: For mild neurocognitive disorder due to any of the medical etiologies listed above, code 331.83 (631.84). Do not use additional codes for the presumed etiological medical conditions. For substance/medication-induced mild neurocognitive disorder, code based on type of substance; see “Substance/Medication-Induced Major or Mild Neurocog- nitive Disorder." For unspecified mild neurocognitive disorder, code 799.59 (R41.9).
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).
Major and mild neurocognitive disorders (NCDs) are primarily subtyped according to the known or presumed etiological/ pathological entity or entities underlying the cognitive de- cline. These subtypes are distinguished on the basis of a combination of time course, charac- teristic domains affected, and associated symptoms. For certain etiological subtypes, the diagnosis depends substantially on the presence of a potentially causative entity, such as Par- kinson’s or Huntington’s disease, or a traumatic brain injury or stroke in the appropriate time period. For other etiological subtypes (generally the neurodegenerative diseases like Alzhei- mer’s disease, frontotemporal lobar degeneration, and Lewy body disease), the diagnosis is based primarily on the cognitive, behavioral, and functional symptoms. Typically, the differ- 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 correlation with underlying brain pathology. The subtype criteria here have been harmonized with those expert criteria.
Evidence for distinct behavioral features in NCDs has been recognized, particularly in the areas of psychotic symptoms and depression. Psychotic features are common in many
NCDs, particularly at the mild-to-moderate stage of major NCDs due to Alzheimer’s dis- ease, Lewy body disease, and frontotemporal lobar degeneration. Paranoia and other delusions are common features, and often a persecutory theme may be a prominent aspect of delusional ideation. In contrast to psychotic disorders with onset in earlier life (e.g., schizophrenia), disorganized speech and disorganized behavior are not characteristic of psychosis in NCDs. Hallucinations may occur in any modality, although visual hallucina- tions are more common in NCDs than in depressive, bipolar, or psychotic disorders.