Uniform Data Set version 4
UDSv4 - Template

United States

Reference ID

USDv4

Producer(s)

National Alzheimer’s Coordinating Center (NACC) and the NIA-funded ADRC network

Collections

Clinical Trial

Metadata

DDI/XML JSON

Created on

Jul 02, 2026

Last modified

Jul 07, 2026

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11405

Variable Groups

Variable group: D1a Clinical Syndrome

Variables 181

alcdem

27. Cognitive impairment due to alcohol use or abuse

alcdemif

27a. Cognitive impairment due to alcohol abuse (primary/contributing/non-contributing)

amndem

8a. Amnestic predominant syndrome

anxiet

14. Anxiety disorder (DSM-5-TR criteria*)

anxietif

14a. Anxiety disorder (primary/contributing/non-contributing)

apneadx

25. Sleep apnea (i.e., obstructive, central, mixed or complex sleep apnea)

apneadxif

25a. Sleep apnea (i.e., obstructive, central, mixed or complex sleep apnea) (primary/contributing/non-contributing)

bdomafreg

7b. MBI affected domains - Affective regulation

bdomimp

7c. MBI affected domains - Impulse control

bdommot

7a. MBI affected domains - Motivation

bdomsocial

7d. MBI affected domains - Social appropriateness

bdomthts

7e. MBI affected domains - Thought content/perception

bipoldif

12a. Bipolar disorder (primary/contributing/non-contributing)

bipoldx

12. Bipolar disorder (DSM-5-TR criteria*)

cbssyn

8j. Corticobasal syndrome (CBS) syndrome

cdomaprax

6g. Dementia and MCI affected domains - Apraxia

cdomattn

6c. Dementia and MCI affected domains - Attention

cdombeh

6f. Dementia and MCI affected domains - Behavioral

cdomexec

6d. Dementia and MCI affected domains - Executive

cdomlang

6b. Dementia and MCI affected domains - Language

cdommem

6a. Dementia and MCI affected domains - Memory

cdomvisu

6e. Dementia and MCI affected domains - Visuospatial

cogoth

30. Cognitive impairment not otherwise specified (NOS)

cogoth2

31. Cognitive impairment not otherwise specified (NOS)

cogoth2f

31a. Cognitive impairment NOS (primary/contributing/non-contributing)

cogoth2x

31b. Cognitive impairment NOS (specify)

cogoth3

32. Cognitive impairment not otherwise specified (NOS)

cogoth3f

32a. Cognitive impairment NOS (primary/contributing/non-contributing)

cogoth3x

32b. Cognitive impairment NOS (specify)

cogothif

30a. Cognitive impairment NOS (primary/contributing/non-contributing)

cogothx

30b. Cognitive impairment NOS (specify)

ctesyn

8i. Traumatic encephalopathy syndrome

d1a_clinical_syndrome_compl
ete

delir

17. Delirium (DSM-5-TR criteria*)

delirif

17a. Delirium (primary/contributing/non-contributing)

demented

3. Does the participant meet the criteria for dementia?

dxmethod

1. Diagnosis method-responses in this form are based on diagnosis by a:

dyexecsyn

8b. Dysexecutive predominant syndrome

epilep

epilepif

20a. Epilepsy (primary/contributing/non-contributing)

frmdated1a

0a. D1a Clinical Diagnosis - Form date

ftdsyn

8e. Behavioral variant frontotemporal (bvFTD) syndrome

genanx

14b. Generalized anxiety disorder

hiv

23. Human immunodeficiency virus (HIV) infection

hivif

23a. Human Immunodeficiency Virus (HIV) infection (primary/contributing/non-contributing)

hyceph

21. Normal-pressure hydrocephalus

hycephif

21a. Normal-pressure hydrocephalus (primary/contributing/non-contributing)

impnomci

5b. Does the participant meet any criteria for cognitively impaired, not MCI/dementia?

impnomcicg

5a2. Cognitively impaired, not MCI reason - Cognitive testing is abnormal but no clinical concern or functional decline (e.g., CDR SB=0 and FAS=0)

impnomcifu

5a1. Cognitively impaired, not MCI reason - Evidence of functional impairment (e.g., CDR SB>0 and/or FAS>0), but available cognitive testing is judged to be normal

impnomcio

5a4. Cognitively impaired, not MCI reason - Other

impnomciox

5a4a. Cognitively impaired, not MCI reason - Other (specify)

impnomclcd

5a3. Cognitively impaired, not MCI reason - Longstanding cognitive difficulties, not representing a change from their usual function

impsub

28. Cognitive impairment due to substance use or abuse

impsubif

28a. Cognitive impairment due to substance use or abuse (primary/contributing/non-contributing)

initialsd1a

0b. D1a Clinical Diagnosis - Examiner's Initials

langd1a

0c. D1a Clinical Diagnosis - Language

lbdsyn

8f. Lewy body syndrome

lbdsynt

8f1. If present, select one:

loc_alcdem

27. Cognitive impairment due to alcohol use or abuse

loc_alcdemif

alcdemif primary?

loc_anxiet

14. Anxiety disorder (DSM-5-TR criteria*)

loc_anxietif

anxietif primary?

loc_apneadx

25. Sleep apnea (i.e., obstructive, central, mixed or complex sleep apnea)

loc_apneadxif

apneadxif primary?

loc_bipoldif

bipoldif primary?

loc_bipoldx

12. Bipolar disorder (DSM-5-TR criteria*)

loc_cdomaprax

6g. Dementia and MCI affected domains - Apraxia

loc_cdomattn

6c. Dementia and MCI affected domains - Attention

loc_cdombeh

6f. Dementia and MCI affected domains - Behavioral

loc_cdomexec

6d. Dementia and MCI affected domains - Executive

loc_cdomlang

6b. Dementia and MCI affected domains - Language

loc_cdommem

6a. Dementia and MCI affected domains - Memory

loc_cdomvisu

6e. Dementia and MCI affected domains - Visuospatial

loc_cogoth

30. Cognitive impairment not otherwise specified (NOS)

loc_cogoth2

31. Cognitive impairment not otherwise specified (NOS)

loc_cogoth2f

cogoth2f primary?

loc_cogoth3

32. Cognitive impairment not otherwise specified (NOS)

loc_cogoth3f

cogoth3f primary?

loc_cogothif

cogothif primary?

loc_d1a_condall

Sum of D1a Diagnoses 10-32 marked as primary

loc_d1a_condset1

Sum of D1a Conditions 10-14 marked as primary

loc_d1a_condset2

Sum of D1a Conditions 15-18 marked as primary

loc_d1a_condset3

Sum of D1a Conditions 19-22 marked as primary

loc_d1a_condset4

Sum of D1a Conditions 23-26 marked as primary

loc_d1a_condset5

Sum of D1a Conditions 27-32 marked as primary

loc_delir

17. Delirium (DSM-5-TR criteria*)

loc_delirif

delirif primary?

loc_epilep

loc_epilepif

epilepif primary?

loc_genanx

14b. Generalized anxiety disorder

loc_hiv

23. Human immunodeficiency virus (HIV) infection

loc_hivif

loc_hyceph

21. Normal-pressure hydrocephalus

loc_hycephif

hycephif primary?

loc_impnomci

5. Cognitively impaired, not MCI reason

loc_impnomci_sum

D1a Sum of questions 5a1 - 5a4

loc_impsub

28. Cognitive impairment due to substance use or abuse

loc_impsubif

impsubif primary?

loc_majdepdif

majdepdif primary?

loc_majdepdx

10. Major depressive disorder (DSM-5-TR criteria*)

loc_mcicrit

4. MCI core clinical criteria

loc_mcicrit_sum

D1a Sum of questions 4a1 - 4a3

loc_meds

29. Cognitive impairment due to medications

loc_medsif

medsif primary?

loc_ndevdis

16. Developmental neuropsychiatric disorders (e.g., autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD), dyslexia)

loc_ndevdisif

ndevdisif primary?

loc_neop

22. CNS Neoplasm

loc_neopif

neopif primary?

loc_ocddx

14d. Obsessive-compulsive disorder (OCD)

loc_othanxd

14e. Other anxiety disorder

loc_othcillif

othcillif primary?

loc_othcogill

26. Cognitive impairment due to other neurologic, genetic, infectious conditions (not listed above), or systemic disease/medical illness (as indicated on Form A5/D2)

loc_othdepdif

othdepdif primary?

loc_othdepdx

11. Other specified depressive disorder (DSM-5-TR criteria*)

loc_othpsy

18. Other psychiatric disorder (DSM-5-TR criteria*)

loc_othpsyif

othpsyif primary?

loc_panicdisdx

14c. Panic Disorder

loc_postc19

24. Post COVID-19 cognitive impairment

loc_postc19if

postc19if primary?

loc_predomsynpres

8a-l. Select the predominant syndrome as present; all others will default to Absent in the NACC database.

loc_ptsddx

15. Post-traumatic stress disorder (PTSD)(DSM-5-TR criteria*)

loc_ptsddxif

ptsddxif primary?

loc_schizoif

schizoif primary?

loc_schizop

13. Schizophrenia or other psychotic disorder (DSM-5-TR criteria*)

loc_syninfbiom

9c. Biomarkers (MRI, PET, CSF, plasma)

loc_syninfclin

9a. Clinical information (history, CDR)

loc_syninfctst

9b. Cognitive testing

loc_tbidx

19. Traumatic brain injury (Distinct from TES and CTE, which are documented as a Clinical Syndrome and Etiologic Diagnosis, respectively)

loc_tbidxif

tbidxif primary?

majdepdif

10a. Major depressive disorder (primary/contributing/non-contributing)

majdepdx

10. Major depressive disorder (DSM-5-TR criteria*)

mbi

7. Does the participant meet criteria for MBI

mci

4b. Does the participant meet criteria for MCI (amnestic or non-amnestic)?

mcicritcln

4a1. MCI criteria - Clinical concern about decline in cognition compared to participant's prior level of lifelong or usual cognitive function

mcicritfun

4a3. MCI criteria - Largely preserved functional independence OR functional dependence that is not related to cognitive decline

mcicritimp

4a2. MCI criteria - Impairment in one or more cognitive domains, compared to participant's estimated prior level of lifelong or usual cognitive function, or supported by objective longitudinal neuropsychological evidence of decline

meds

29. Cognitive impairment due to medications

medsif

29a. Cognitive impairment due to medications (primary/contributing/non-contributing)

msasyn

8k. Multiple system atrophy (MSA) syndrome

msasynt

8k1. If present, select one:

namndem

8g. Non-amnestic multidomain syndrome, not PCA, PPA, bvFTD, or DLB syndrome

ndevdis

16. Developmental neuropsychiatric disorders (e.g., autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD), dyslexia)

ndevdisif

16a. Developmental neuropsychiatric disorders (e.g., autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (primary/contributing/non-contributing)

neop

22. CNS Neoplasm

neopif

22a. CNS Neoplasm (primary/contributing/non-contributing)

neopstat

22b. CNS Neoplasm - benign or malignant

normcog

2. Does the participant have unimpaired cognition & behavior

ocddx

14d. Obsessive-compulsive disorder (OCD)

othanxd

14e. Other anxiety disorder

othanxdx

14e1. Other anxiety disorder (specify)

othcillif

26a. Cognitive impairment due to other neurologic, genetic, infectious conditions (not listed above), or systemic disease/medical illness (as indicated on Form A5/D2) (primary/contributing/non-contributing)

othcogill

26. Cognitive impairment due to other neurologic, genetic, infectious conditions (not listed above), or systemic disease/medical illness (as indicated on Form A5/D2)

othcogillx

26b. Specify cognitive impairment due to other neurologic, genetic, infection conditions or systemic disease

othdepdif

11a. Other specified depressive disorder (primary/contributing/non-contributing)

othdepdx

11. Other specified depressive disorder (DSM-5-TR criteria*)

othpsy

18. Other psychiatric disorder (DSM-5-TR criteria*)

othpsyif

18a. Other psychiatric disorder (primary/contributing/non-contributing)

othpsyx

18b. Other psychiatric disorder (specify)

othsyn

othsynx

8l1. Other (SPECIFY):

panicdisdx

14c. Panic Disorder

pca

8c. Primary visual presentation (such as posterior cortical atrophy (PCA) syndrome)

postc19

24. Post COVID-19 cognitive impairment

postc19if

24a. Post COVID-19 cognitive impairment (primary/contributing/non-contributing)

ppasyn

8d. Primary progressive aphasia (PPA) syndrome

ppasynt

8d1. If present, select one:

predomsyn

8. Is there a predominant clinical syndrome?

pspsyn

8h. Primary supranuclear palsy (PSP) syndrome

pspsynt

8h1. If present, select one:

ptsddx

15. Post-traumatic stress disorder (PTSD)(DSM-5-TR criteria*)

ptsddxif

15a. Post-traumatic stress disorder (PTSD) (primary/contributing/non-contributing)

scd

2a. Does the participant report 1) significant concerns about changes in cognition AND 2) no neuropsychological evidence of decline AND 3) no functional decline?

scddxconf

2b. As a clinician, are you confident that the subjective cognitive decline is clinically meaningful?

schizoif

13a. Schizophrenia or other psychotic disorder (primary/contributing/non-contributing)

schizop

13. Schizophrenia or other psychotic disorder (DSM-5-TR criteria*)

syninfbiom

9c. Biomarkers (MRI, PET, CSF, plasma)

syninfclin

9a. Clinical information (history, CDR)

syninfctst

9b. Cognitive testing

tbidx

19. Traumatic brain injury (Distinct from TES and CTE, which are documented as a Clinical Syndrome and Etiologic Diagnosis, respectively)

tbidxif

19a. Traumatic brain injury (primary/contributing/non-contributing)

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