Clinical trials data
Cognitive tests in anxiety, PTSD and OCD trials: 692 registered studies
Every registered anxiety, PTSD and OCD study on ClinicalTrials.gov that names a cognitive test in an outcome measure: the tests used most, how often as a primary outcome, which tests go together, how large the studies are and when they measure the outcome.
- Registered anxiety, PTSD and OCD studies name a cognitive test in an outcome
- 692
- Led by industry
- 33
The tests anxiety, PTSD and OCD trials use most
The Stroop Color-Word Test leads: 79 of the 692 studies name it, 11%. Next comes the Digit Span Test (72). As a primary outcome, the Go/No-Go Task leads with 28 studies.
- 1
Stroop Color-Word Test79 studies, 23 as a primary outcome
- 2
Digit Span Test72 studies, 27 as a primary outcome
- 3
Verbal Learning70 studies, 27 as a primary outcome
- 4
Trail Making Test69 studies, 24 as a primary outcome
- 5
Go/No-Go Task63 studies, 28 as a primary outcome
- 6
Verbal Fluency61 studies, 23 as a primary outcome
- 7
Dot-Probe Task40 studies, 18 as a primary outcome
- 8
Continuous Performance Test37 studies, 10 as a primary outcome
- 9
N-Back Task31 studies, 12 as a primary outcome
- 10
Symbol Coding31 studies, 10 as a primary outcome
- 11
Stop-Signal Task29 studies, 14 as a primary outcome
- 12
Card Sorting Test (Berg)29 studies, 8 as a primary outcome
- 13
Eriksen Flanker Task22 studies, 7 as a primary outcome
- 14
Tower Planning19 studies, 6 as a primary outcome
- 15
Emotion Regulation Task16 studies, 13 as a primary outcome
- 16
AX Continuous Performance Test16 studies, 1 as a primary outcome
- 17
Attention Network Test15 studies, 3 as a primary outcome
- 18
Emotional Stroop Task15 studies, 3 as a primary outcome
- 19
Iowa Gambling Lite15 studies, 2 as a primary outcome
- 20
Emoji Emotion Recognition14 studies, 5 as a primary outcome
- 21
Letter-Number Sequencing Task14 studies, 3 as a primary outcome
- 22
Paced Visual Serial Addition Test13 studies, 8 as a primary outcome
- 23
Word-Sentence Association Task13 studies, 7 as a primary outcome
- 24
Scrambled Sentences Test13 studies, 6 as a primary outcome
- 25
Rapid Visual Information Processing13 studies, 3 as a primary outcome
A test as a primary outcomeOnly in secondary or other outcomes
16% of anxiety, PTSD and OCD studies name only instruments outside the library, such as clinician-administered screening scales. They count in every figure on this page and are not listed. The explorer below holds all 143 tests.
Tests used together
- Digit Span Test and Trail Making Test30 studies name both
- Trail Making Test and Verbal Fluency27 studies name both
- Digit Span Test and Verbal Fluency25 studies name both
- Digit Span Test and Verbal Learning23 studies name both
- Stroop Color-Word Test and Trail Making Test22 studies name both
- Trail Making Test and Verbal Learning22 studies name both
- Verbal Fluency and Verbal Learning22 studies name both
- Stroop Color-Word Test and Verbal Learning17 studies name both
- AX Continuous Performance Test and Continuous Performance Test16 studies name both
- Digit Span Test and Stroop Color-Word Test13 studies name both
Studies by start year
A test as a primary outcomeOnly in secondary or other outcomes
Show as a table
| Start year | Studies | A test as a primary outcome |
|---|---|---|
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 1 | 1 |
| 2003 | 2 | 2 |
| 2004 | 6 | 4 |
| 2005 | 1 | 0 |
| 2006 | 2 | 0 |
| 2007 | 4 | 2 |
| 2008 | 4 | 2 |
| 2009 | 8 | 4 |
| 2010 | 8 | 3 |
| 2011 | 15 | 4 |
| 2012 | 16 | 4 |
| 2013 | 17 | 3 |
| 2014 | 22 | 8 |
| 2015 | 27 | 13 |
| 2016 | 31 | 14 |
| 2017 | 42 | 13 |
| 2018 | 35 | 15 |
| 2019 | 49 | 17 |
| 2020 | 32 | 12 |
| 2021 | 64 | 30 |
| 2022 | 53 | 20 |
| 2023 | 53 | 21 |
| 2024 | 71 | 34 |
| 2025 | 70 | 25 |
| 2026 | 54 | 19 |
Phases and sponsors
By phase
- Early phase 115 studies, 3 as a primary outcome
- Phase 116 studies, 9 as a primary outcome
- Phase 1/216 studies, 7 as a primary outcome
- Phase 250 studies, 20 as a primary outcome
- Phase 2/36 studies, 0 as a primary outcome
- Phase 313 studies, 3 as a primary outcome
- Phase 421 studies, 10 as a primary outcome
- Not applicable472 studies, 188 as a primary outcome
- Observational83 studies, 33 as a primary outcome
Sponsors and study types
Lead sponsor: industry 33, NIH 8, universities, hospitals and others 651. Interventional 609, observational 83.
Status, results, interventions and countries
Status
- Recruiting138 studies, 49 as a primary outcome
- Not yet recruiting32 studies, 10 as a primary outcome
- Active, not recruiting24 studies, 7 as a primary outcome
- Completed355 studies, 159 as a primary outcome
- Stopped early55 studies, 21 as a primary outcome
- Status unknown88 studies, 27 as a primary outcome
What they test
- Behavioral302 studies, 117 as a primary outcome
- Drug123 studies, 49 as a primary outcome
- Device119 studies, 48 as a primary outcome
- Dietary supplement36 studies, 17 as a primary outcome
- Procedure13 studies, 5 as a primary outcome
- Diagnostic test11 studies, 5 as a primary outcome
- Biological3 studies, 2 as a primary outcome
- Radiation2 studies, 1 as a primary outcome
- Genetic1 studies, 0 as a primary outcome
- Other140 studies, 52 as a primary outcome
- None given32 studies, 14 as a primary outcome
Intervention types as registered. A study can list several; observational studies often list none.
Where their sites are
- United States311 studies, 140 as a primary outcome
- Canada48 studies, 17 as a primary outcome
- United Kingdom33 studies, 9 as a primary outcome
- China32 studies, 9 as a primary outcome
- France28 studies, 5 as a primary outcome
- Germany23 studies, 9 as a primary outcome
- Türkiye21 studies, 8 as a primary outcome
- Israel20 studies, 3 as a primary outcome
- Spain16 studies, 9 as a primary outcome
- Sweden15 studies, 2 as a primary outcome
- Netherlands14 studies, 1 as a primary outcome
- Denmark10 studies, 2 as a primary outcome
51 countries in all. A study with sites in several counts in each; 34 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 anxiety, PTSD and OCD studies: 152 of 355, 43%
Every completed study with a cognitive outcome: 3,626 of 7,953, 46%
| Results | Completed anxiety, PTSD and OCD studies | Every completed study |
|---|---|---|
| Results on ClinicalTrials.gov and a paper | 35, 10% | 776, 10% |
| Results on ClinicalTrials.gov only | 57, 16% | 1,139, 14% |
| A results paper only | 60, 17% | 1,711, 22% |
| Neither | 203, 57% | 4,327, 54% |
How many participants they enroll
- Early phase 125 median, 20 to 60
- Phase 138 median, 11 to 41
- Phase 1/242 median, 25 to 65
- Phase 262 median, 41 to 104
- Phase 370 median, 35 to 140
- Phase 465 median, 46 to 100
- Not applicable69 median, 40 to 120
- Observational109 median, 60 to 350
Show as a table
| Phase | Studies with a size | Median | Middle half |
|---|---|---|---|
| Early phase 1 | 15 | 25 | 20 to 60 |
| Phase 1 | 15 | 38 | 11 to 41 |
| Phase 1/2 | 14 | 42 | 25 to 65 |
| Phase 2 | 47 | 62 | 41 to 104 |
| Phase 3 | 12 | 70 | 35 to 140 |
| Phase 4 | 21 | 65 | 46 to 100 |
| Not applicable | 465 | 69 | 40 to 120 |
| Observational | 81 | 109 | 60 to 350 |
When the cognitive outcome is measured
Latest time point of each outcome
- Within a day181 outcomes, 64 as a primary outcome
- Up to 4 weeks222 outcomes, 73 as a primary outcome
- 1 to 3 months428 outcomes, 153 as a primary outcome
- 3 to 6 months229 outcomes, 64 as a primary outcome
- 6 to 12 months71 outcomes, 24 as a primary outcome
- 1 to 2 years28 outcomes, 14 as a primary outcome
- Over 2 years32 outcomes, 16 as a primary outcome
- No duration given69 outcomes, 36 as a primary outcome
A test as a primary outcomeOnly in secondary or other outcomes
1,191 of the 1,260 outcome measures give a duration. A single visit counts as within a day.
Median time to the primary outcome, by test
| Test | Primary outcomes | Median |
|---|---|---|
| Digit Span Test | 25 | 6 weeks |
| Go/No-Go Task | 25 | 10 weeks |
| Verbal Learning | 22 | 13 weeks |
| Stroop Color-Word Test | 21 | 8 weeks |
| Trail Making Test | 21 | 13 weeks |
| Verbal Fluency | 21 | 13 weeks |
| Dot-Probe Task | 17 | 4 weeks |
| Stop-Signal Task | 13 | 7 weeks |
| Emotion Regulation Task | 12 | 12 weeks |
| N-Back Task | 11 | 13 weeks |
Explore the anxiety, PTSD and OCD studies
583 studies match. 242 name a library test in a primary outcome. Median size 70 participants. Median time to the primary outcome: 9 weeks.
Loading 583 studies; the filters turn on when they arrive.
2026 is partly planned starts. Not shown: 4 planned to start after 2026.
Show as a table
| Start year | Studies | As a primary outcome |
|---|---|---|
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 1 | 1 |
| 2003 | 2 | 2 |
| 2004 | 6 | 4 |
| 2005 | 1 | 0 |
| 2006 | 2 | 0 |
| 2007 | 3 | 2 |
| 2008 | 4 | 2 |
| 2009 | 6 | 3 |
| 2010 | 8 | 3 |
| 2011 | 13 | 3 |
| 2012 | 15 | 4 |
| 2013 | 16 | 3 |
| 2014 | 19 | 7 |
| 2015 | 24 | 13 |
| 2016 | 28 | 12 |
| 2017 | 39 | 13 |
| 2018 | 29 | 13 |
| 2019 | 44 | 16 |
| 2020 | 22 | 11 |
| 2021 | 56 | 26 |
| 2022 | 44 | 17 |
| 2023 | 46 | 19 |
| 2024 | 60 | 30 |
| 2025 | 49 | 18 |
| 2026 | 42 | 17 |
Library tests named most
Largest condition groups
Phases
Participants
Lead sponsor: industry 31, NIH 8, other 544. Interventional 532, observational 51.
As a primary outcomeSecondary or other outcome
The studies, newest registration first
Each number opens the study's record on ClinicalTrials.gov.
| Study | Start | Phase | Conditions | Participants | Lead sponsor | Status | Library tests named, with the latest time point |
|---|---|---|---|---|---|---|---|
| NCT07903896 | Start2026 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD | Participants75 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07902076 | Start2027 | PhaseObservational | ConditionsAnxiety, PTSD and OCD | Participants280 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07898722 | Start2025 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD, Pain and fatigue | Participants40 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT07872917 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants20 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07871916 | Start2026 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Anxiety, PTSD and OCD | Participants96 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07866794 | Start2026 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Anxiety, PTSD and OCD | Participants135 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07864103 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07861919 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants40 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07852910 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD, Lung disease | Participants18 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07829510 | Start2026 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Substance use and addiction, Anxiety, PTSD and OCD | Participants300 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07818876 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants72 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07816861 | Start2025 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07810595 | Start2025 | PhaseNot applicable | ConditionsHealthy volunteers, Aging, frailty and exercise, Anxiety, PTSD and OCD | Participants48 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT07810348 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants75 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT07805200 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants80 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07794228 | Start2026 | PhaseNot applicable | ConditionsHealthy volunteers, Anxiety, PTSD and OCD | Participants30 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT07765355 | Start2025 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Anxiety, PTSD and OCD | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07763977 | Start2024 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07755839 | Start2026 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Cancer, Anxiety, PTSD and OCD | Participants60 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07753538 | Start2024 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants50 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT07752342 | Start2026 | PhaseNot applicable | ConditionsHealthy volunteers, Anxiety, PTSD and OCD | Participants150 | Lead sponsorIndustry | StatusNot yet recruiting | Library tests named
|
| NCT07750925 | Start2026 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Healthy volunteers, Anxiety, PTSD and OCD | Participants45 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07745335 | Start2026 | PhaseNot applicable | ConditionsAnxiety, PTSD and OCD | Participants240 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07735910 | Start2026 | PhaseNot applicable | ConditionsMild cognitive impairment, Depression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07717866 | Start2022 | PhaseObservational | ConditionsBrain injury and concussion, Depression and bipolar disorder, Anxiety, PTSD and OCD | Participants52 | Lead sponsorIndustry | StatusActive, not recruiting | Library tests named
|
Questions, answered from the data
Which cognitive test do anxiety, PTSD and OCD trials use most?
The Stroop Color-Word Test: 79 of the 692 registered studies name it in an outcome measure, 11%. Next come the Digit Span Test (72) and Verbal Learning (70).
Which cognitive test do anxiety, PTSD and OCD trials use most as a primary outcome?
The Go/No-Go Task, named in a primary outcome by 28 studies. 273 of the 692 studies, 39%, name a cognitive test in a primary outcome.
How many participants does a phase 2 anxiety, PTSD and OCD trial enroll?
Half of the phase 2 anxiety, PTSD and OCD studies enroll 62 participants or fewer, and the middle half enroll 41 to 104. 47 of them give a size.
How long after the start do anxiety, PTSD and OCD trials measure a cognitive outcome?
Half of the primary outcomes that name a library test are measured within 9 weeks of the start, and the middle half from 2 weeks to 5 months. 408 primary outcomes give a duration.
Which cognitive tests do anxiety, PTSD and OCD trials use together?
The Digit Span Test with the Trail Making Test most often: 30 studies name both. Next, the Trail Making Test with Verbal Fluency (27).
How many completed anxiety, PTSD and OCD trials have reported results?
152 of the 355 completed anxiety, PTSD and OCD studies, 43%, have reported results: 92 posted them on ClinicalTrials.gov, 95 have a results paper linked to the registry record, and 35 did both. The other 203 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.
Plan the cognitive outcomes of a anxiety, PTSD and OCD trial
Choose tests with a record in registered trials, and run them in a browser at every site, on the same version each visit.