Clinical trials data

Category Fluency in dementia and Alzheimer's trials: 167 registered studies

Every registered dementia and Alzheimer's disease study on ClinicalTrials.gov that names Category Fluency in an outcome measure: how often it is a primary outcome, the tests named with it, how large the studies are and when they measure it.

Registered dementia and Alzheimer's disease studies name it in an outcome measure: 167
Name it in a primary outcome, 30%: 50 of 167
Of the condition's 1,673 studies name it, against 4% of all registered studies: 10%; Other conditions
Median participants per study: 81; By phase

Try Category Fluency

Tests named in the same studies

The library tests that dementia and Alzheimer's disease studies naming Category Fluency name most often beside it.

1
Verbal Fluency93 studies, 28 as a primary outcome
2
Trail Making Test71 studies, 28 as a primary outcome
3
Digit Span Test65 studies, 20 as a primary outcome
4
Verbal Learning57 studies, 27 as a primary outcome
5
Symbol Coding42 studies, 19 as a primary outcome
6
Short Story Recall39 studies, 18 as a primary outcome
7
Picture Naming Test39 studies, 13 as a primary outcome
8
Selective Reminding Task23 studies, 7 as a primary outcome
9
Stroop Color-Word Test19 studies, 8 as a primary outcome
10
Clock Drawing Task17 studies, 8 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

Studies by start year

Each study counted once. 2026 is partly planned starts.

A test as a primary outcomeOnly in secondary or other outcomes

Show as a table

Registered studies by start year
Start year	Studies	A test as a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	0
2004	2	0
2005	3	1
2006	0	0
2007	1	0
2008	2	0
2009	2	1
2010	3	0
2011	5	4
2012	6	2
2013	4	1
2014	3	1
2015	6	1
2016	8	2
2017	6	0
2018	9	6
2019	12	4
2020	7	1
2021	16	6
2022	17	7
2023	14	4
2024	10	2
2025	17	3
2026	9	3

Phases and study sizes

By phase

Early phase 13 studies, 1 as a primary outcome
Phase 17 studies, 0 as a primary outcome
Phase 1/25 studies, 0 as a primary outcome
Phase 250 studies, 17 as a primary outcome
Phase 2/34 studies, 0 as a primary outcome
Phase 314 studies, 3 as a primary outcome
Phase 43 studies, 0 as a primary outcome
Not applicable60 studies, 18 as a primary outcome
Observational21 studies, 11 as a primary outcome

Participants per study

Phase 289 median, 42 to 162
Phase 3755 median, 279 to 1,550
Not applicable58 median, 35 to 121
Observational417 median, 90 to 1,697

Participants per study. The bar spans the middle half of the studies in each phase, the mark is the median, and the axis is logarithmic. Phases with fewer than 10 studies that give a size are left out.

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Participants per dementia and Alzheimer's disease study that names Category Fluency, by phase
Phase	Studies with a size	Median	Middle half
Phase 2	48	89	42 to 162
Phase 3	14	755	279 to 1,550
Not applicable	60	58	35 to 121
Observational	19	417	90 to 1,697

When dementia and Alzheimer's trials measure it

Half of the primary outcomes that name Category Fluency are measured within 6 months of the start, and the middle half from 12 weeks to 18 months. 45 primary outcomes give a duration.

Latest time point of each outcome

Within a day4 outcomes, 3 as a primary outcome
Up to 4 weeks5 outcomes, 1 as a primary outcome
1 to 3 months29 outcomes, 10 as a primary outcome
3 to 6 months50 outcomes, 15 as a primary outcome
6 to 12 months20 outcomes, 4 as a primary outcome
1 to 2 years26 outcomes, 5 as a primary outcome
Over 2 years21 outcomes, 7 as a primary outcome
No duration given11 outcomes, 5 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

155 of the 166 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

Recruiting32 studies, 8 as a primary outcome
Not yet recruiting7 studies, 0 as a primary outcome
Active, not recruiting14 studies, 5 as a primary outcome
Completed81 studies, 25 as a primary outcome
Stopped early23 studies, 9 as a primary outcome
Status unknown10 studies, 3 as a primary outcome

What they test

Behavioral30 studies, 11 as a primary outcome
Drug73 studies, 15 as a primary outcome
Device29 studies, 9 as a primary outcome
Dietary supplement6 studies, 2 as a primary outcome
Procedure1 studies, 1 as a primary outcome
Diagnostic test3 studies, 1 as a primary outcome
Biological12 studies, 2 as a primary outcome
Radiation4 studies, 2 as a primary outcome
Combination product1 studies, 1 as a primary outcome
Genetic1 studies, 1 as a primary outcome
Other30 studies, 14 as a primary outcome
None given11 studies, 8 as a primary outcome

Intervention types as registered. A study can list several; observational studies often list none.

49 countries in all. A study with sites in several counts in each; 8 list no site.

Reported results

Completed studies with results posted on ClinicalTrials.gov, a results paper the registry links to the study, or both.

Completed dementia and Alzheimer's disease studies that name Category Fluency: 56 of 81, 69%

Every completed study with a cognitive outcome: 3,626 of 7,953, 46%

Completed dementia and Alzheimer's disease studies that name Category Fluency and every completed study, by how they reported results
Results	Completed dementia and Alzheimer's disease studies that name Category Fluency	Every completed study
Results on ClinicalTrials.gov and a paper	28, 35%	776, 10%
Results on ClinicalTrials.gov only	10, 12%	1,139, 14%
A results paper only	18, 22%	1,711, 22%
Neither	25, 31%	4,327, 54%

The 167 studies

Filter by phase, sponsor, status, country, intervention, outcome list, size and start year. Each study links to its record on ClinicalTrials.gov.

167 studies match. 50 name Category Fluency in a primary outcome. Median size 81 participants. Median time to the primary outcome: 6 months.

Loading 167 studies; the filters turn on when they arrive.

By start year

2026 is partly planned starts. Not shown: 1 that started before 2000 and 3 planned to start after 2026.

Show as a table

Matching studies by start year
Start year	Studies	As a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	0
2004	2	0
2005	3	1
2006	0	0
2007	1	0
2008	2	0
2009	2	1
2010	3	0
2011	5	4
2012	6	2
2013	4	1
2014	3	1
2015	6	1
2016	8	2
2017	6	0
2018	9	6
2019	12	4
2020	7	1
2021	16	6
2022	17	7
2023	14	4
2024	10	2
2025	17	3
2026	9	3

Library tests named most

Largest condition groups

Dementia and Alzheimer's167 studies, 50 as a primary outcome
Mild cognitive impairment42 studies, 11 as a primary outcome
Parkinson's disease11 studies, 4 as a primary outcome
Aging, frailty and exercise6 studies, 3 as a primary outcome
Obesity and diabetes5 studies, 3 as a primary outcome
Cancer3 studies, 0 as a primary outcome
Sleep and sleep disorders3 studies, 1 as a primary outcome
Depression and bipolar disorder2 studies, 0 as a primary outcome
Healthy volunteers2 studies, 1 as a primary outcome
Stroke1 study, 0 as a primary outcome
Multiple sclerosis1 study, 0 as a primary outcome
Hearing loss1 study, 1 as a primary outcome

Phases

Participants

Lead sponsor: industry 48, other 119. Interventional 146, observational 21.

As a primary outcomeSecondary or other outcomeCategory Fluency

The studies, newest registration first

Each number opens the study's record on ClinicalTrials.gov.

Registered studies that match the filters, newest registration first, with the library tests each one names and the outcome list that names them.
Study	Start	Phase	Conditions	Participants	Lead sponsor	Status	Library tests named, with the latest time point
NCT07882251	Start2021	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants80	Lead sponsorOther	StatusCompleted	Library tests named Stroop Color-Word TestPrimary5 weeks Verbal LearningPrimary5 weeks Digit Span TestPrimary5 weeks Category FluencyPrimary5 weeks Complex Figure Copy and RecallPrimary5 weeks Corsi Block-Tapping TestPrimary5 weeks Line Angle MatchingPrimary5 weeks
NCT07842146	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants60	Lead sponsorOther	StatusRecruiting	Library tests named Verbal FluencySecondary11 months Symbol CodingSecondary11 months Category FluencySecondary11 months Delayed Recall ModuleSecondary11 months
NCT07839650	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Verbal LearningPrimary6 months Category FluencyPrimary6 months Task Switching TestPrimary6 months Face-name Memory TaskPrimary6 months
NCT07786116	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Parkinson's disease, Sleep and sleep disorders	Participants215	Lead sponsorOther	StatusRecruiting	Library tests named Category FluencyOther outcome18 months
NCT07722169	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants48	Lead sponsorOther	StatusNot yet recruiting	Library tests named Verbal FluencySecondary13 weeks Digit Span TestSecondary13 weeks Category FluencySecondary13 weeks Picture Naming TestSecondary13 weeks Matrix ReasoningSecondary13 weeks Token Commands TaskSecondary13 weeks
NCT07717411	Start2026	PhasePhase 3	ConditionsDementia and Alzheimer's	Participants1,600	Lead sponsorIndustry	StatusRecruiting	Library tests named Trail Making TestSecondary4 years Symbol CodingSecondary4 years Category FluencySecondary4 years Short Story RecallSecondary4 years Selective Reminding TaskSecondary4 years
NCT07651085	Start2024	PhaseObservational	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Parkinson's disease, Sleep and sleep disorders	Participants65	Lead sponsorOther	StatusActive, not recruiting	Library tests named Verbal LearningPrimary Verbal FluencyPrimary Category FluencyPrimary Clock Drawing TaskPrimary
NCT07638813	Start2026	PhasePhase 1/2	ConditionsDementia and Alzheimer's	Participants33	Lead sponsorOther	StatusNot yet recruiting	Library tests named Verbal FluencySecondary6 months Category FluencySecondary6 months Picture Naming TestSecondary6 months
NCT07505784	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary Verbal FluencyPrimary Digit Span TestPrimary Go/No-Go TaskPrimary Category FluencyPrimary Task Switching TestPrimary Emoji Emotion RecognitionPrimary
NCT07402356	Start2025	PhaseObservational	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Depression and bipolar disorder	Participants140	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Verbal LearningSecondary6 months Verbal FluencySecondary6 months N-Back TaskPrimarysame day Category FluencySecondary6 months Picture Naming TestSecondary6 months
NCT07399418	Start2025	PhaseObservational	ConditionsDementia and Alzheimer's	Participants80	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimarysame day Stroop Color-Word TestPrimarysame day Verbal FluencyPrimarysame day Digit Span TestPrimarysame day Go/No-Go TaskPrimarysame day Category FluencyPrimarysame day Clock Drawing TaskPrimarysame day Complex Figure Copy and RecallPrimarysame day Matrix ReasoningPrimarysame day Selective Reminding TaskPrimarysame day
NCT07392723	Start2025	PhasePhase 2	ConditionsDementia and Alzheimer's, Aging, frailty and exercise	Participants20	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Digit Span TestSecondary6 months Category FluencySecondary6 months Delayed Recall ModuleSecondary6 months
NCT07385937	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants150	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary18 months Verbal FluencySecondary18 months Digit Span TestSecondary18 months Category FluencySecondary18 months Clock Drawing TaskSecondary18 months Cancellation TestSecondary18 months Delayed Recall ModuleSecondary18 months
NCT07375771	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary12 weeks Verbal LearningPrimary12 weeks Verbal FluencyPrimary12 weeks Digit Span TestPrimary12 weeks Category FluencyPrimary12 weeks Task Switching TestPrimary12 weeks Clock Drawing TaskPrimary12 weeks Complex Figure Copy and RecallPrimary12 weeks Visual Search TestPrimary12 weeks
NCT07366346	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants100	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary5 months Verbal LearningPrimary5 months Verbal FluencyPrimary5 months Category FluencyPrimary5 months
NCT07241598	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants70	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary12 months Verbal FluencySecondary12 months Digit Span TestSecondary12 months Symbol CodingSecondary12 months Go/No-Go TaskSecondary12 months Category FluencySecondary12 months
NCT07210528	Start2025	PhasePhase 1	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants48	Lead sponsorOther	StatusActive, not recruiting	Library tests named Digit Span TestSecondary12 weeks Category FluencySecondary12 weeks Picture Naming TestSecondary12 weeks Short Story RecallSecondary12 weeks
NCT07143734	Start2025	PhasePhase 2	ConditionsDementia and Alzheimer's	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Category FluencySecondary12 weeks
NCT07064226	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants102	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Verbal FluencySecondary6 months Category FluencySecondary6 months Selective Reminding TaskSecondary6 months
NCT07036328	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants55	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Verbal LearningSecondary6 months Verbal FluencySecondary6 months Digit Span TestSecondary6 months Category FluencySecondary6 months Task Switching TestSecondary6 months
NCT07033481	Start2025	PhasePhase 2	ConditionsDementia and Alzheimer's	Participants20	Lead sponsorIndustry	StatusActive, not recruiting	Library tests named Stroop Color-Word TestOther outcome8 months Verbal FluencyOther outcome8 months Category FluencyOther outcome8 months
NCT07031167	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants100	Lead sponsorOther	StatusNot yet recruiting	Library tests named Category FluencyOther outcome2 years
NCT06953167	Start2025	PhaseObservational	ConditionsDementia and Alzheimer's	Participants600	Lead sponsorOther	StatusRecruiting	Library tests named Symbol CodingPrimary8.5 years Category FluencyPrimary8.5 years Short Story RecallPrimary8.5 years Selective Reminding TaskPrimary8.5 years
NCT06861231	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants22	Lead sponsorOther	StatusCompleted Results Paper	Library tests named Verbal LearningSecondary6 weeks Category FluencyOther outcome6 weeks
NCT06832761	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants300	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary12 months Verbal LearningSecondary12 months Digit Span TestSecondary12 months Symbol CodingSecondary12 months Category FluencySecondary12 months

Questions, answered from the data

How many dementia and Alzheimer's trials use Category Fluency?

167 registered dementia and Alzheimer's disease studies on ClinicalTrials.gov name it in an outcome measure, 50 of them in a primary outcome: 10% of the condition's 1,673 studies with a cognitive outcome, against 4% of all of them. It is the 5th most named test in dementia and Alzheimer's trials.

Which tests do dementia and Alzheimer's trials use with Category Fluency?

Verbal Fluency (93 studies), the Trail Making Test (71 studies) and the Digit Span Test (65 studies).

How many participants do phase 2 dementia and Alzheimer's trials that use Category Fluency enroll?

Half of the phase 2 studies that name it enroll 89 participants or fewer, and the middle half enroll 42 to 162. 48 of them give a size.

When do dementia and Alzheimer's trials measure Category Fluency?

Half of the primary outcomes that name Category Fluency are measured within 6 months of the start, and the middle half from 12 weeks to 18 months. 45 primary outcomes give a duration.

How many completed dementia and Alzheimer's trials that use Category Fluency have reported results?

56 of the 81 completed studies that name it, 69%, have reported results: 38 posted them on ClinicalTrials.gov, 46 have a results paper linked to the registry record, and 28 did both. The other 25 show neither. Of all completed studies with a cognitive outcome, 46% have reported results.

How the studies are counted

For each test family, the census runs ClinicalTrials.gov's own outcome search for the family's names and reads every study first posted by the day the family was counted. These studies were read on 10 November 2026. A study counts once on a page, however many tests it names. Counts for a test cover every version of the task under any of its names, so a page can count studies that used a commercial version.

The census adds two things to each record and changes nothing in it: which outcome list names the test (primary, then secondary, then other), and the condition groups, matched on the study's condition names and MeSH terms. A study can fall in several groups; one whose only condition is cognitive impairment or decline falls in “Cognitive impairment and decline”. Studies that name only instruments outside the library count in every total and share but are not listed.

A second read on 10 November 2026 added each study's overall status, whether results are posted, its intervention types, the countries of its sites and the time frame of the outcome that names each test. A time frame counts by the latest time point it names: “Baseline, 12 and 24 weeks” is 24 weeks, a single visit is within a day, and one that names no duration, such as “end of treatment”, is left out of the timings.

A third read on 10 November 2026 added the papers the registry links to each study: those its sponsor lists as reporting results, and those PubMed links to it through the study's NCT number. A study has a results paper when one of them came out in or after the month of its primary completion and PubMed does not class it as a protocol, review or comment. A paper that never gives the NCT number is not linked, so some studies counted as reporting neither did publish.

Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine, which does not endorse these pages. Every study line is in the data release 2.1.0, and the explorer's own file is clinical-trials-studies.json.

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Clinical trials data

Category Fluency in dementia and Alzheimer's trials: 167 registered studies

Registered dementia and Alzheimer's disease studies name it in an outcome measure: 167
Name it in a primary outcome, 30%: 50 of 167
Of the condition's 1,673 studies name it, against 4% of all registered studies: 10%; Other conditions
Median participants per study: 81; By phase

Try Category Fluency

Tests named in the same studies

The library tests that dementia and Alzheimer's disease studies naming Category Fluency name most often beside it.

1
Verbal Fluency93 studies, 28 as a primary outcome
2
Trail Making Test71 studies, 28 as a primary outcome
3
Digit Span Test65 studies, 20 as a primary outcome
4
Verbal Learning57 studies, 27 as a primary outcome
5
Symbol Coding42 studies, 19 as a primary outcome
6
Short Story Recall39 studies, 18 as a primary outcome
7
Picture Naming Test39 studies, 13 as a primary outcome
8
Selective Reminding Task23 studies, 7 as a primary outcome
9
Stroop Color-Word Test19 studies, 8 as a primary outcome
10
Clock Drawing Task17 studies, 8 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

Studies by start year

Each study counted once. 2026 is partly planned starts.

A test as a primary outcomeOnly in secondary or other outcomes

Show as a table

Registered studies by start year
Start year	Studies	A test as a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	0
2004	2	0
2005	3	1
2006	0	0
2007	1	0
2008	2	0
2009	2	1
2010	3	0
2011	5	4
2012	6	2
2013	4	1
2014	3	1
2015	6	1
2016	8	2
2017	6	0
2018	9	6
2019	12	4
2020	7	1
2021	16	6
2022	17	7
2023	14	4
2024	10	2
2025	17	3
2026	9	3

Phases and study sizes

By phase

Early phase 13 studies, 1 as a primary outcome
Phase 17 studies, 0 as a primary outcome
Phase 1/25 studies, 0 as a primary outcome
Phase 250 studies, 17 as a primary outcome
Phase 2/34 studies, 0 as a primary outcome
Phase 314 studies, 3 as a primary outcome
Phase 43 studies, 0 as a primary outcome
Not applicable60 studies, 18 as a primary outcome
Observational21 studies, 11 as a primary outcome

Participants per study

Phase 289 median, 42 to 162
Phase 3755 median, 279 to 1,550
Not applicable58 median, 35 to 121
Observational417 median, 90 to 1,697

Show as a table

Participants per dementia and Alzheimer's disease study that names Category Fluency, by phase
Phase	Studies with a size	Median	Middle half
Phase 2	48	89	42 to 162
Phase 3	14	755	279 to 1,550
Not applicable	60	58	35 to 121
Observational	19	417	90 to 1,697

When dementia and Alzheimer's trials measure it

Half of the primary outcomes that name Category Fluency are measured within 6 months of the start, and the middle half from 12 weeks to 18 months. 45 primary outcomes give a duration.

Latest time point of each outcome

Within a day4 outcomes, 3 as a primary outcome
Up to 4 weeks5 outcomes, 1 as a primary outcome
1 to 3 months29 outcomes, 10 as a primary outcome
3 to 6 months50 outcomes, 15 as a primary outcome
6 to 12 months20 outcomes, 4 as a primary outcome
1 to 2 years26 outcomes, 5 as a primary outcome
Over 2 years21 outcomes, 7 as a primary outcome
No duration given11 outcomes, 5 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

155 of the 166 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

Recruiting32 studies, 8 as a primary outcome
Not yet recruiting7 studies, 0 as a primary outcome
Active, not recruiting14 studies, 5 as a primary outcome
Completed81 studies, 25 as a primary outcome
Stopped early23 studies, 9 as a primary outcome
Status unknown10 studies, 3 as a primary outcome

What they test

Behavioral30 studies, 11 as a primary outcome
Drug73 studies, 15 as a primary outcome
Device29 studies, 9 as a primary outcome
Dietary supplement6 studies, 2 as a primary outcome
Procedure1 studies, 1 as a primary outcome
Diagnostic test3 studies, 1 as a primary outcome
Biological12 studies, 2 as a primary outcome
Radiation4 studies, 2 as a primary outcome
Combination product1 studies, 1 as a primary outcome
Genetic1 studies, 1 as a primary outcome
Other30 studies, 14 as a primary outcome
None given11 studies, 8 as a primary outcome

Intervention types as registered. A study can list several; observational studies often list none.

49 countries in all. A study with sites in several counts in each; 8 list no site.

Reported results

Completed studies with results posted on ClinicalTrials.gov, a results paper the registry links to the study, or both.

Completed dementia and Alzheimer's disease studies that name Category Fluency: 56 of 81, 69%

Every completed study with a cognitive outcome: 3,626 of 7,953, 46%

Completed dementia and Alzheimer's disease studies that name Category Fluency and every completed study, by how they reported results
Results	Completed dementia and Alzheimer's disease studies that name Category Fluency	Every completed study
Results on ClinicalTrials.gov and a paper	28, 35%	776, 10%
Results on ClinicalTrials.gov only	10, 12%	1,139, 14%
A results paper only	18, 22%	1,711, 22%
Neither	25, 31%	4,327, 54%

The 167 studies

Filter by phase, sponsor, status, country, intervention, outcome list, size and start year. Each study links to its record on ClinicalTrials.gov.

167 studies match. 50 name Category Fluency in a primary outcome. Median size 81 participants. Median time to the primary outcome: 6 months.

Loading 167 studies; the filters turn on when they arrive.

By start year

2026 is partly planned starts. Not shown: 1 that started before 2000 and 3 planned to start after 2026.

Show as a table

Matching studies by start year
Start year	Studies	As a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	0
2004	2	0
2005	3	1
2006	0	0
2007	1	0
2008	2	0
2009	2	1
2010	3	0
2011	5	4
2012	6	2
2013	4	1
2014	3	1
2015	6	1
2016	8	2
2017	6	0
2018	9	6
2019	12	4
2020	7	1
2021	16	6
2022	17	7
2023	14	4
2024	10	2
2025	17	3
2026	9	3

Library tests named most

Largest condition groups

Dementia and Alzheimer's167 studies, 50 as a primary outcome
Mild cognitive impairment42 studies, 11 as a primary outcome
Parkinson's disease11 studies, 4 as a primary outcome
Aging, frailty and exercise6 studies, 3 as a primary outcome
Obesity and diabetes5 studies, 3 as a primary outcome
Cancer3 studies, 0 as a primary outcome
Sleep and sleep disorders3 studies, 1 as a primary outcome
Depression and bipolar disorder2 studies, 0 as a primary outcome
Healthy volunteers2 studies, 1 as a primary outcome
Stroke1 study, 0 as a primary outcome
Multiple sclerosis1 study, 0 as a primary outcome
Hearing loss1 study, 1 as a primary outcome

Phases

Participants

Lead sponsor: industry 48, other 119. Interventional 146, observational 21.

As a primary outcomeSecondary or other outcomeCategory Fluency

The studies, newest registration first

Each number opens the study's record on ClinicalTrials.gov.

Registered studies that match the filters, newest registration first, with the library tests each one names and the outcome list that names them.
Study	Start	Phase	Conditions	Participants	Lead sponsor	Status	Library tests named, with the latest time point
NCT07882251	Start2021	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants80	Lead sponsorOther	StatusCompleted	Library tests named Stroop Color-Word TestPrimary5 weeks Verbal LearningPrimary5 weeks Digit Span TestPrimary5 weeks Category FluencyPrimary5 weeks Complex Figure Copy and RecallPrimary5 weeks Corsi Block-Tapping TestPrimary5 weeks Line Angle MatchingPrimary5 weeks
NCT07842146	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants60	Lead sponsorOther	StatusRecruiting	Library tests named Verbal FluencySecondary11 months Symbol CodingSecondary11 months Category FluencySecondary11 months Delayed Recall ModuleSecondary11 months
NCT07839650	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Verbal LearningPrimary6 months Category FluencyPrimary6 months Task Switching TestPrimary6 months Face-name Memory TaskPrimary6 months
NCT07786116	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Parkinson's disease, Sleep and sleep disorders	Participants215	Lead sponsorOther	StatusRecruiting	Library tests named Category FluencyOther outcome18 months
NCT07722169	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants48	Lead sponsorOther	StatusNot yet recruiting	Library tests named Verbal FluencySecondary13 weeks Digit Span TestSecondary13 weeks Category FluencySecondary13 weeks Picture Naming TestSecondary13 weeks Matrix ReasoningSecondary13 weeks Token Commands TaskSecondary13 weeks
NCT07717411	Start2026	PhasePhase 3	ConditionsDementia and Alzheimer's	Participants1,600	Lead sponsorIndustry	StatusRecruiting	Library tests named Trail Making TestSecondary4 years Symbol CodingSecondary4 years Category FluencySecondary4 years Short Story RecallSecondary4 years Selective Reminding TaskSecondary4 years
NCT07651085	Start2024	PhaseObservational	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Parkinson's disease, Sleep and sleep disorders	Participants65	Lead sponsorOther	StatusActive, not recruiting	Library tests named Verbal LearningPrimary Verbal FluencyPrimary Category FluencyPrimary Clock Drawing TaskPrimary
NCT07638813	Start2026	PhasePhase 1/2	ConditionsDementia and Alzheimer's	Participants33	Lead sponsorOther	StatusNot yet recruiting	Library tests named Verbal FluencySecondary6 months Category FluencySecondary6 months Picture Naming TestSecondary6 months
NCT07505784	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary Verbal FluencyPrimary Digit Span TestPrimary Go/No-Go TaskPrimary Category FluencyPrimary Task Switching TestPrimary Emoji Emotion RecognitionPrimary
NCT07402356	Start2025	PhaseObservational	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Depression and bipolar disorder	Participants140	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Verbal LearningSecondary6 months Verbal FluencySecondary6 months N-Back TaskPrimarysame day Category FluencySecondary6 months Picture Naming TestSecondary6 months
NCT07399418	Start2025	PhaseObservational	ConditionsDementia and Alzheimer's	Participants80	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimarysame day Stroop Color-Word TestPrimarysame day Verbal FluencyPrimarysame day Digit Span TestPrimarysame day Go/No-Go TaskPrimarysame day Category FluencyPrimarysame day Clock Drawing TaskPrimarysame day Complex Figure Copy and RecallPrimarysame day Matrix ReasoningPrimarysame day Selective Reminding TaskPrimarysame day
NCT07392723	Start2025	PhasePhase 2	ConditionsDementia and Alzheimer's, Aging, frailty and exercise	Participants20	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Digit Span TestSecondary6 months Category FluencySecondary6 months Delayed Recall ModuleSecondary6 months
NCT07385937	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants150	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary18 months Verbal FluencySecondary18 months Digit Span TestSecondary18 months Category FluencySecondary18 months Clock Drawing TaskSecondary18 months Cancellation TestSecondary18 months Delayed Recall ModuleSecondary18 months
NCT07375771	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary12 weeks Verbal LearningPrimary12 weeks Verbal FluencyPrimary12 weeks Digit Span TestPrimary12 weeks Category FluencyPrimary12 weeks Task Switching TestPrimary12 weeks Clock Drawing TaskPrimary12 weeks Complex Figure Copy and RecallPrimary12 weeks Visual Search TestPrimary12 weeks
NCT07366346	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants100	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary5 months Verbal LearningPrimary5 months Verbal FluencyPrimary5 months Category FluencyPrimary5 months
NCT07241598	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants70	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary12 months Verbal FluencySecondary12 months Digit Span TestSecondary12 months Symbol CodingSecondary12 months Go/No-Go TaskSecondary12 months Category FluencySecondary12 months
NCT07210528	Start2025	PhasePhase 1	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants48	Lead sponsorOther	StatusActive, not recruiting	Library tests named Digit Span TestSecondary12 weeks Category FluencySecondary12 weeks Picture Naming TestSecondary12 weeks Short Story RecallSecondary12 weeks
NCT07143734	Start2025	PhasePhase 2	ConditionsDementia and Alzheimer's	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Category FluencySecondary12 weeks
NCT07064226	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants102	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Verbal FluencySecondary6 months Category FluencySecondary6 months Selective Reminding TaskSecondary6 months
NCT07036328	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants55	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Verbal LearningSecondary6 months Verbal FluencySecondary6 months Digit Span TestSecondary6 months Category FluencySecondary6 months Task Switching TestSecondary6 months
NCT07033481	Start2025	PhasePhase 2	ConditionsDementia and Alzheimer's	Participants20	Lead sponsorIndustry	StatusActive, not recruiting	Library tests named Stroop Color-Word TestOther outcome8 months Verbal FluencyOther outcome8 months Category FluencyOther outcome8 months
NCT07031167	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants100	Lead sponsorOther	StatusNot yet recruiting	Library tests named Category FluencyOther outcome2 years
NCT06953167	Start2025	PhaseObservational	ConditionsDementia and Alzheimer's	Participants600	Lead sponsorOther	StatusRecruiting	Library tests named Symbol CodingPrimary8.5 years Category FluencyPrimary8.5 years Short Story RecallPrimary8.5 years Selective Reminding TaskPrimary8.5 years
NCT06861231	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants22	Lead sponsorOther	StatusCompleted Results Paper	Library tests named Verbal LearningSecondary6 weeks Category FluencyOther outcome6 weeks
NCT06832761	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's	Participants300	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary12 months Verbal LearningSecondary12 months Digit Span TestSecondary12 months Symbol CodingSecondary12 months Category FluencySecondary12 months

Questions, answered from the data

How many dementia and Alzheimer's trials use Category Fluency?

Which tests do dementia and Alzheimer's trials use with Category Fluency?

Verbal Fluency (93 studies), the Trail Making Test (71 studies) and the Digit Span Test (65 studies).

How many participants do phase 2 dementia and Alzheimer's trials that use Category Fluency enroll?

Half of the phase 2 studies that name it enroll 89 participants or fewer, and the middle half enroll 42 to 162. 48 of them give a size.

When do dementia and Alzheimer's trials measure Category Fluency?

Half of the primary outcomes that name Category Fluency are measured within 6 months of the start, and the middle half from 12 weeks to 18 months. 45 primary outcomes give a duration.

How many completed dementia and Alzheimer's trials that use Category Fluency have reported results?

How the studies are counted

Run Category Fluency in your trial

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Category Fluency in dementia and Alzheimer's trials: 167 registered studies

Tests named in the same studies

Studies by start year

Phases and study sizes

By phase

Participants per study

When dementia and Alzheimer's trials measure it

Latest time point of each outcome

Status, results, interventions and countries

Status

What they test

Where their sites are

Reported results

The 167 studies

Library tests named most

Largest condition groups

Phases

Participants

The studies, newest registration first

Questions, answered from the data

How many dementia and Alzheimer's trials use Category Fluency?

Which tests do dementia and Alzheimer's trials use with Category Fluency?

How many participants do phase 2 dementia and Alzheimer's trials that use Category Fluency enroll?

When do dementia and Alzheimer's trials measure Category Fluency?

How many completed dementia and Alzheimer's trials that use Category Fluency have reported results?

More on Category Fluency and dementia and Alzheimer's disease

Category Fluency in other conditions

Other tests in dementia and Alzheimer's trials

How the studies are counted

Run Category Fluency in your trial

Category Fluency in dementia and Alzheimer's trials: 167 registered studies

Tests named in the same studies

Studies by start year

Phases and study sizes

By phase

Participants per study

When dementia and Alzheimer's trials measure it

Latest time point of each outcome

Status, results, interventions and countries

Status

What they test

Where their sites are

Reported results

The 167 studies

Library tests named most

Largest condition groups

Phases

Participants

The studies, newest registration first

Questions, answered from the data

How many dementia and Alzheimer's trials use Category Fluency?

Which tests do dementia and Alzheimer's trials use with Category Fluency?

How many participants do phase 2 dementia and Alzheimer's trials that use Category Fluency enroll?

When do dementia and Alzheimer's trials measure Category Fluency?

How many completed dementia and Alzheimer's trials that use Category Fluency have reported results?

More on Category Fluency and dementia and Alzheimer's disease

Category Fluency in other conditions

Other tests in dementia and Alzheimer's trials

How the studies are counted

Run Category Fluency in your trial