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Condition (MeSH)

Brain Diseases

ClinicalTrials.gov lists 37,155 trials for Brain Diseases or a narrower condition beneath it. National Institute of Neurological Disorders and Stroke (NINDS) has the most among industry and government lead sponsors, with 278.

MeSH D001927 Nervous System Diseases C10
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Phase 1 Phase 1 2,640 Phase 1/2 Phase 1/2 897 Phase 2 Phase 2 3,595 Phase 2/3 Phase 2/3 457 Phase 3 Phase 3 2,464 Phase 4 Phase 4 1,614 Not applicable Not applicable 15,548 Observational Observational 9,842 Phase 1 Phase 1 2,640 Phase 1/2 Phase 1/2 897 Phase 2 Phase 2 3,595 Phase 2/3 Phase 2/3 457 Phase 3 Phase 3 2,464 Phase 4 Phase 4 1,614 Not applicable Not applicable 15,548 Observational Observational 9,842

Trials per phase (log scale)

2 more sections with rows

497 of the 37,155 trials are tagged with Brain Diseases itself; the rest are tagged with a narrower condition beneath it.

Get the Brain Diseases report as a PDF

The PDF carries up to 50 rows of each section, where the page shows the first few, with the sources listed. Enter a work email and confirm it from the message we send, and the report follows by email.

When did Brain Diseases trials start? (37)

Shown in this order: most recent first, 1990 onwards. 2026 is partial: trials registered with a 2026 start date so far, not a full year. 109 trials are registered to start in 2027 or later, and not listed here.

Trials over time, by phase

  • Phase 1
  • Phase 1/2
  • Phase 2
  • Phase 2/3
  • Phase 3
  • Phase 4
  • Not applicable
  • Observational
  • Other (Expanded access, Unknown)

Top of scale: 2,633

1990: 8 trials (Observational 6, Phase 2 1, Phase 1/2 1) 1991: 17 trials (Observational 13, Phase 3 1, Phase 2 2, Phase 1 1) 1992: 20 trials (Observational 11, Not applicable 1, Phase 4 1, Phase 3 4, Phase 2 2, Phase 1 1) 1993: 30 trials (Observational 13, Not applicable 1, Phase 4 2, Phase 3 5, Phase 2 5, Phase 1/2 1, Phase 1 3) 1994: 30 trials (Observational 10, Not applicable 2, Phase 4 1, Phase 3 6, Phase 2 7, Phase 1 4) 1995: 42 trials (Observational 16, Not applicable 4, Phase 4 1, Phase 3 14, Phase 2/3 2, Phase 2 3, Phase 1/2 1, Phase 1 1) 1996: 41 trials (Observational 12, Not applicable 4, Phase 4 3, Phase 3 6, Phase 2/3 1, Phase 2 9, Phase 1 6) 1997: 64 trials (Observational 24, Not applicable 5, Phase 4 4, Phase 3 9, Phase 2 13, Phase 1/2 1, Phase 1 8) 1998: 83 trials (Observational 22, Not applicable 5, Phase 4 6, Phase 3 18, Phase 2/3 2, Phase 2 18, Phase 1/2 3, Phase 1 9) 1999: 106 trials (Observational 34, Not applicable 6, Phase 4 6, Phase 3 17, Phase 2/3 2, Phase 2 27, Phase 1/2 2, Phase 1 12) 2000: 161 trials (Observational 44, Not applicable 16, Phase 4 6, Phase 3 26, Phase 2/3 2, Phase 2 39, Phase 1/2 10, Phase 1 18) 2001: 197 trials (Observational 54, Not applicable 18, Phase 4 14, Phase 3 44, Phase 2/3 5, Phase 2 31, Phase 1/2 9, Phase 1 22) 2002: 280 trials (Observational 61, Not applicable 42, Phase 4 23, Phase 3 51, Phase 2/3 5, Phase 2 55, Phase 1/2 14, Phase 1 29) 2003: 365 trials (Other 1, Observational 98, Not applicable 45, Phase 4 41, Phase 3 64, Phase 2/3 10, Phase 2 69, Phase 1/2 14, Phase 1 23) 2004: 446 trials (Observational 93, Not applicable 66, Phase 4 49, Phase 3 88, Phase 2/3 8, Phase 2 87, Phase 1/2 15, Phase 1 40) 2005: 550 trials (Observational 113, Not applicable 81, Phase 4 62, Phase 3 92, Phase 2/3 9, Phase 2 116, Phase 1/2 14, Phase 1 63) 2006: 628 trials (Observational 140, Not applicable 109, Phase 4 73, Phase 3 98, Phase 2/3 12, Phase 2 115, Phase 1/2 13, Phase 1 68) 2007: 780 trials (Observational 184, Not applicable 142, Phase 4 75, Phase 3 109, Phase 2/3 14, Phase 2 129, Phase 1/2 23, Phase 1 104) 2008: 802 trials (Observational 182, Not applicable 151, Phase 4 66, Phase 3 101, Phase 2/3 19, Phase 2 141, Phase 1/2 31, Phase 1 111) 2009: 919 trials (Other 1, Observational 214, Not applicable 199, Phase 4 72, Phase 3 100, Phase 2/3 22, Phase 2 163, Phase 1/2 36, Phase 1 112) 2010: 934 trials (Observational 255, Not applicable 228, Phase 4 63, Phase 3 102, Phase 2/3 18, Phase 2 118, Phase 1/2 38, Phase 1 112) 2011: 983 trials (Observational 277, Not applicable 252, Phase 4 48, Phase 3 81, Phase 2/3 14, Phase 2 165, Phase 1/2 43, Phase 1 103) 2012: 1,098 trials (Other 1, Observational 306, Not applicable 338, Phase 4 67, Phase 3 87, Phase 2/3 19, Phase 2 128, Phase 1/2 45, Phase 1 107) 2013: 1,217 trials (Observational 307, Not applicable 496, Phase 4 70, Phase 3 85, Phase 2/3 16, Phase 2 107, Phase 1/2 35, Phase 1 101) 2014: 1,385 trials (Other 1, Observational 362, Not applicable 581, Phase 4 73, Phase 3 69, Phase 2/3 18, Phase 2 136, Phase 1/2 36, Phase 1 109) 2015: 1,501 trials (Observational 405, Not applicable 631, Phase 4 80, Phase 3 90, Phase 2/3 24, Phase 2 127, Phase 1/2 31, Phase 1 113) 2016: 1,629 trials (Other 1, Observational 411, Not applicable 735, Phase 4 68, Phase 3 78, Phase 2/3 27, Phase 2 157, Phase 1/2 37, Phase 1 115) 2017: 1,675 trials (Observational 444, Not applicable 783, Phase 4 53, Phase 3 83, Phase 2/3 22, Phase 2 143, Phase 1/2 40, Phase 1 107) 2018: 1,903 trials (Observational 527, Not applicable 877, Phase 4 67, Phase 3 101, Phase 2/3 20, Phase 2 159, Phase 1/2 36, Phase 1 116) 2019: 2,076 trials (Other 1, Observational 589, Not applicable 980, Phase 4 63, Phase 3 88, Phase 2/3 12, Phase 2 169, Phase 1/2 40, Phase 1 134) 2020: 1,902 trials (Observational 550, Not applicable 917, Phase 4 59, Phase 3 81, Phase 2/3 15, Phase 2 127, Phase 1/2 41, Phase 1 112) 2021: 2,471 trials (Other 2, Observational 751, Not applicable 1,203, Phase 4 60, Phase 3 105, Phase 2/3 22, Phase 2 168, Phase 1/2 45, Phase 1 115) 2022: 2,370 trials (Observational 693, Not applicable 1,165, Phase 4 67, Phase 3 111, Phase 2/3 13, Phase 2 163, Phase 1/2 47, Phase 1 111) 2023: 2,566 trials (Observational 749, Not applicable 1,334, Phase 4 66, Phase 3 85, Phase 2/3 24, Phase 2 145, Phase 1/2 44, Phase 1 119) 2024: 2,633 trials (Observational 701, Not applicable 1,412, Phase 4 64, Phase 3 91, Phase 2/3 28, Phase 2 156, Phase 1/2 43, Phase 1 138) 2025: 2,571 trials (Observational 602, Not applicable 1,409, Phase 4 58, Phase 3 122, Phase 2/3 21, Phase 2 180, Phase 1/2 47, Phase 1 132)

Trials registered with a start date in each year, 1990 onward, stacked by phase (complete years only; the current partial year is in the table's notes). The table below lists the same counts, most recent years first.

Trials started per year
Year Trials started
2026 (partial year) 2,281
2025 2,571
2024 2,633
2023 2,566
2022 2,370
2021 2,471
2020 1,902
2019 2,076
2018 1,903
2017 1,675

Forecast of the full-year count, planned starts included, not rows of this table: about 2,900 trials starting in 2026 and about 2,600 in 2027, the average of the 24 months through September, counted as registered and carried forward, with about 0.7 times the starts already registered for the rest of 2026 added. The rows of this table count trials registered so far with a start date in the year, planned starts included; the forecast looks ahead to the count for the whole year, so it is not the same measure. In backtests on conditions of this size, forecasts made part-way through the year were typically off by about 10 percent and ran about 4 percent high against the count later registered; forecasts made before the year began were off by about 25 percent and ran about 15 percent low against the count later registered, and had about 7 percent more error than repeating last year's count. The part-way figures are from forecasts that used a multiple fitted only on earlier years. A stricter check that trains only on older years did not support adding planned starts for conditions of this size: it ran about 6 percent high against the count later registered. These figures rest on a few years of history (target years from 2018 to 2025, varying by figure), place each condition as it is mapped today rather than as it was then, and score against a count for the newest year that was still being revised. Only condition series were scored.

Prediction, not a registry value: median of 36 months from start to primary completion across 3,732 trials still running at the 2026-10-09 snapshot; registered median of 24 months across 21,074 trials with a primary completion typed Actual. Source: ClinicalTrials.gov / AACT (CTTI), public domain.

What phase are Brain Diseases trials in? (10)

Shown in this order: phase order.

Show the trials by phase as a table
Trials by phase
Phase Trials
Phase 1 2,640
Phase 1/2 897
Phase 2 3,595
Phase 2/3 457
Phase 3 2,464
Phase 4 1,614
Not applicable 15,548
Observational 9,842
Expanded access 94
Unknown 4

How many Brain Diseases trials are recruiting? (13)

Shown in this order: the order a trial moves through, from not yet recruiting to unknown.

Trials by recruitment status
Status Trials
Not yet recruiting 1,944
Recruiting 5,179
Enrolling by invitation 433
Active, not recruiting 1,326
Available 29

Status as registered on ClinicalTrials.gov. Each trial is counted once.

Which lead sponsors run the most Brain Diseases trials? (3)

Shown in this order: most trials first. Lead sponsors the registry classes as industry, NIH, US federal, other government or network. A hospital or university the registry files as government can appear here. Sponsors it classes as academic or other are shown on the full page, because that class cannot separate an institution from a named investigator.

Lead sponsors
Sponsor Trials
National Institute of Neurological Disorders and Stroke (NINDS) 278
VA Office of Research and Development 256
Pfizer 215

Interventions as named in the registry (15)

Shown in this order: most trials first.

Interventions as named in the registry
Drug Trials
SOC: Temozolomide 163
Donepezil HCI (drug) 157
EC Aspirin 143
Control (placebo) group 133
Levetiracetam XR 126

These are the names sponsors entered on ClinicalTrials.gov that we have not matched to a single molecule. Some are drugs under a brand or code name; others are procedures, doses or arm labels.

Which serious adverse events do Brain Diseases trials report? (10)

Shown in this order: most subjects affected first. Subjects affected summed across trials, a cross-trial signal, not a rate.

Serious adverse events in this condition's trials
Adverse event Subjects affected Trials
Other 16,432 24
Pneumonia 6,368 679
MVE 6,060 1
Surgical and medical procedures 5,478 6
Cardiac disorders 3,961 12

Which publications cover Brain Diseases? (802)

Shown in this order: major-topic papers first, then newest, then most linked to trials.

Sub-conditions in MeSH (32)

MeSH descendants one level down with at least one trial, most trials first.

+22 more sub-conditions

Not on this page

Not measured: delivery record.

Checked, with nothing recorded for this condition: prevalence and rare-disease identity.

Browse all condition evidence pages