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ORPHA:33208

Idiopathic hypersomnia

low confidenceDisorder

Also known as: Idiopathic excessive sleepiness

Publications

1,544

Trials

37

Interventional, condition-specific

Researchers

867

Distinct authors in sample

Gene link

—

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare neurologic disease characterized by an excessive daytime sleepiness with long and unrefreshing naps, and/or prolonged and undisturbed nocturnal sleep, impaired daytime alertness, and/or sleep inertia (ie, great difficulty in waking up after sleep) and where other causes have been excluded.

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (1)

primary hypersomnia

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

4/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    1,544 matched papers (1,028 in last 10 years) Source

  3. Phenotype characterisedPresent

    12 HPO annotations (e.g. Excessive daytime somnolence; Hypnagogic hallucination; Sleep disturbance) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationPresent

    2 FDA · 4 EMA designations (2 FDA orphan-indication approvals) — e.g. Gamma-hydroxybutyric acid Source

  6. Interventional trialPresent

    37 matched on ClinicalTrials.gov (18 recruiting in sample)

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Not yet — the cause hasn't been pinned down in GenCC.

No strong gene–disease assertion joined for this Orphanet entity.

Phenotypes (Monarch / HPO)

12

Associated phenotypes · MONDO:0018044

  • Excessive daytime somnolence
  • Hypnagogic hallucination
  • Sleep disturbance
  • Hypnopompic hallucination

Showing 4 of 12 — open Monarch for the full list.

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

Monarch fetch 2026-07-29

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

6

Designations · 2 with FDA orphan-indication approval

  • FDA Gamma-hydroxybutyric acidIdiopathic Hypersomnia · 2019-07-31 · Not FDA Approved for Orphan Indication
  • FDA pentetrazolIdiopathic Hypersomnia · 2015-09-09 · Not FDA Approved for Orphan Indication
  • EMA serdexmethylphenidateTreatment of idiopathic hypersomnia · 24/05/2024 · PositiveEMA designation
  • EMA MazindolTreatment of idiopathic hypersomnia · 10/08/2022 · PositiveEMA designation
  • EMA sodium oxybate;calcium oxybate;magnesium oxybate;potassium oxybateTreatment of idiopathic hypersomnia · 06/01/2021 · PositiveEMA designation
  • EMA pentetrazolTreatment of idiopathic hypersomnia · 11/11/2015 · WithdrawnEMA designation

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

10

Drugs / clinical candidates · MONDO_0018044

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

1,544

1,544 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

1,544 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

1,028 in the last 10 years · low confidence

Phrase hits: 1,544 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

867

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Dauvilliers Y40 papers · 2026

    From the Sleep-Wake Disorders Unit (L.B., S.C., Y.D.), Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier; National Reference Centre for Orphan Diseases (L.B., Y.D.), Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Montpellier; Institute of Neurosciences of Montpellier (L.B., S.B., I.J., Y.D.), University of Montpellier, INSERM; ToNIC (A.K., A.D.C., A.-S.S., S.S., P.P.), Toulouse NeuroImaging Center, UMR 1214, INSERM, Université Paul-Sabatier, Toulouse; Pediatric Sleep Centre (M.L.), Hospital Robert-Debré; National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome (M.L.), Paris; Sleep Unit of Toulouse Hospital (R.D.), National Competence Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Department of Neurology; CHRU de Tours-Université de Tours (N.A., P.V.), Inserm U1253 « Imaging and Brain » (iBrain), Inserm CIC 1415, Tours; Sleep Unit (E.E.), CHU Nîmes; Radiopharmacy Department (M.A., A.-S.S.), CHU Toulouse; Critical Care Unit (S.S.), Purpan University Hospital, Toulouse; Department of Nuclear Medicine (D.M.-G.), CHU Montpellier; PhyMedExp (D.M.-G.), University of Montpellier, INSERM, CNRS; and Nuclear Medicine Department (P.P.), CHU Toulouse, France.

    Papers in Europe PMC
  2. 02
    Barateau L32 papers · 2026

    From the Sleep-Wake Disorders Unit (L.B., S.C., Y.D.), Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier; National Reference Centre for Orphan Diseases (L.B., Y.D.), Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Montpellier; Institute of Neurosciences of Montpellier (L.B., S.B., I.J., Y.D.), University of Montpellier, INSERM; ToNIC (A.K., A.D.C., A.-S.S., S.S., P.P.), Toulouse NeuroImaging Center, UMR 1214, INSERM, Université Paul-Sabatier, Toulouse; Pediatric Sleep Centre (M.L.), Hospital Robert-Debré; National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome (M.L.), Paris; Sleep Unit of Toulouse Hospital (R.D.), National Competence Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Department of Neurology; CHRU de Tours-Université de Tours (N.A., P.V.), Inserm U1253 « Imaging and Brain » (iBrain), Inserm CIC 1415, Tours; Sleep Unit (E.E.), CHU Nîmes; Radiopharmacy Department (M.A., A.-S.S.), CHU Toulouse; Critical Care Unit (S.S.), Purpan University Hospital, Toulouse; Department of Nuclear Medicine (D.M.-G.), CHU Montpellier; PhyMedExp (D.M.-G.), University of Montpellier, INSERM, CNRS; and Nuclear Medicine Department (P.P.), CHU Toulouse, France.

    Papers in Europe PMC
  3. 03
    Plazzi G16 papers · 2026

    IRCCS-Institute of Neurological Sciences, Bologna, Italy.

    Papers in Europe PMC
  4. 04
    Pizza F13 papers · 2026

    Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy.

    Papers in Europe PMC
  5. 05
    Chenini S12 papers · 2026

    From the Sleep-Wake Disorders Unit (L.B., S.C., Y.D.), Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier; National Reference Centre for Orphan Diseases (L.B., Y.D.), Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Montpellier; Institute of Neurosciences of Montpellier (L.B., S.B., I.J., Y.D.), University of Montpellier, INSERM; ToNIC (A.K., A.D.C., A.-S.S., S.S., P.P.), Toulouse NeuroImaging Center, UMR 1214, INSERM, Université Paul-Sabatier, Toulouse; Pediatric Sleep Centre (M.L.), Hospital Robert-Debré; National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome (M.L.), Paris; Sleep Unit of Toulouse Hospital (R.D.), National Competence Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Department of Neurology; CHRU de Tours-Université de Tours (N.A., P.V.), Inserm U1253 « Imaging and Brain » (iBrain), Inserm CIC 1415, Tours; Sleep Unit (E.E.), CHU Nîmes; Radiopharmacy Department (M.A., A.-S.S.), CHU Toulouse; Critical Care Unit (S.S.), Purpan University Hospital, Toulouse; Department of Nuclear Medicine (D.M.-G.), CHU Montpellier; PhyMedExp (D.M.-G.), University of Montpellier, INSERM, CNRS; and Nuclear Medicine Department (P.P.), CHU Toulouse, France.

    Papers in Europe PMC
  6. 06
    Fuller DS12 papers · 2026

    Biostatistics, Jazz Pharmaceuticals, Philadelphia, PA, USA.

    Papers in Europe PMC
  7. 07
    Plante DT12 papers · 2026

    From the Department of Psychiatry (D.T.P.), and Department of Population Health Sciences (E.W.H., J.H.B., P.E.P.), University of Wisconsin-Madison; and Stanford University Center for Sleep Sciences (E.M.), Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA.

    Papers in Europe PMC
  8. 08
    Jaussent I11 papers · 2026

    From the Sleep-Wake Disorders Unit (L.B., S.C., Y.D.), Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier; National Reference Centre for Orphan Diseases (L.B., Y.D.), Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Montpellier; Institute of Neurosciences of Montpellier (L.B., S.B., I.J., Y.D.), University of Montpellier, INSERM; ToNIC (A.K., A.D.C., A.-S.S., S.S., P.P.), Toulouse NeuroImaging Center, UMR 1214, INSERM, Université Paul-Sabatier, Toulouse; Pediatric Sleep Centre (M.L.), Hospital Robert-Debré; National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome (M.L.), Paris; Sleep Unit of Toulouse Hospital (R.D.), National Competence Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia, and Kleine-Levin Syndrome, Department of Neurology; CHRU de Tours-Université de Tours (N.A., P.V.), Inserm U1253 « Imaging and Brain » (iBrain), Inserm CIC 1415, Tours; Sleep Unit (E.E.), CHU Nîmes; Radiopharmacy Department (M.A., A.-S.S.), CHU Toulouse; Critical Care Unit (S.S.), Purpan University Hospital, Toulouse; Department of Nuclear Medicine (D.M.-G.), CHU Montpellier; PhyMedExp (D.M.-G.), University of Montpellier, INSERM, CNRS; and Nuclear Medicine Department (P.P.), CHU Toulouse, France.

    Papers in Europe PMC
  9. 09
    Whalen M11 papers · 2026

    Jazz Pharmaceuticals, Philadelphia, PA, USA.

    Papers in Europe PMC
  10. 10
    Biscarini F10 papers · 2026

    Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

37

interventional trials for this specific condition

37 interventional trials matched this specific condition name; 18 currently recruiting in our sample. 19 trials are registered for hypersomnia, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 11 September 2026

37 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 96.5th percentile).

low confidence · 96.5th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

37 interventional trials matched after quoted-phrase search and title/condition post-filter.

Broader category: hypersomnia

19

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Observational and natural-history studies

9 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

General rare disease registries you may be eligible for

These studies enroll across many rare conditions. They are not counted as evidence that anyone is studying this specific disease.

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 16 · after dedupe 16 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 16 · dropped 0 · fetched 2026-07-29

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Uncertain / not reviewed (16)

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for Idiopathic hypersomnia — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

"Idiopathic hypersomnia" OR "Idiopathic excessive sleepiness" OR "primary hypersomnia"

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Idiopathic hypersomnia" OR "Idiopathic excessive sleepiness" OR "primary hypersomnia"

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 37 interventional · 9 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"hypersomnia"

Query health: ok — strategies attempted: phrase; with hits: phrase

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus
  • Publication count (1544) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T23:33:05.933Z