Evidence map›Paper›PMID 39511769›Full record

SynthesisPsychiatry and clinical neurosciences2025

Serotonergic underpinnings of obsessive-compulsive disorder: A systematic review and meta-analysis of neuroimaging findings.

Martin Pastre, Bob-Valéry Occéan, Vincent Boudousq, Ismael Conejero, Pascale Fabbro-Peray, Laurent Collombier, Luc Mallet, Jorge Lopez-Castroman

Abstract readSystematic ReviewMeta-Analysis
In one paragraph

Synthesis in Psychiatry and clinical neurosciences, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.

0numbers the graph read from it
0cells of the map it votes in
6citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

6 citing papers in PubMed.

  1. Review
  2. Article
  3. Review
  4. Article
  5. Review
  6. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Martin PastreDepartment of Psychiatry, CHU Nimes, Nimes, France.ORCID https://orcid.org/0000-0002-5560-9847
Bob-Valéry OccéanLaboratoire de Biostatistique, Epidémiologie clinique, Santé Publique Innovation et Méthodologie (BESPIM), CHU Nimes, Nimes, France.
Vincent BoudousqDépartement de Médecine Nucléaire et Biophysique Médicale, CHU Nimes, Nimes, France.
Ismael ConejeroDepartment of Psychiatry, CHU Nimes, Nimes, France.
Pascale Fabbro-PerayLaboratoire de Biostatistique, Epidémiologie clinique, Santé Publique Innovation et Méthodologie (BESPIM), CHU Nimes, Nimes, France.
Laurent CollombierDépartement de Médecine Nucléaire et Biophysique Médicale, CHU Nimes, Nimes, France.
Luc MalletUniversité Paris-Est Créteil, DMU IMPACT, Département Médical-Universitaire de Psychiatrie et d'Addictologie, Hôpitaux Universitaires Henri Mondor-Albert Chenevier, Assistance Publique-Hôpitaux de Paris, Créteil, France.
Jorge Lopez-CastromanDepartment of Psychiatry, CHU Nimes, Nimes, France.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Obsessive-compulsive disorder (OCD) is a frequent and disabling condition, with many patients being treatment-resistant. Improved understanding of its neurobiology is vital for better therapies. Evidence is still conflicting regarding specific serotonergic-related dysfunctions in OCD. We systematically reviewed the literature to provide a quantitative assessment of the role of serotonin (5-HT) in patients with untreated OCD through imaging. We searched for neuroimaging studies investigating central 5-HT tonus in unmedicated patients with OCD, excluding studies comprising treated patients to prevent bias from antidepressant-induced changes in serotonergic tonus. We also conducted a meta-analysis using a homogeneous group of positron emission tomography and single photon emission computed tomography articles that compared 5-HT transporter (SERT) and 5-HT2A receptor (HT2AR) binding potential in different brain regions of patients with untreated OCD and healthy controls. The systematic review encompassed 18 articles, with 13 included in the subsequent meta-analysis. Risk of bias was assessed by a revised form of the Newcastle-Ottawa Scale. We provided standardized mean difference (SMD) values for SERT and 5-HT2AR binding potential measures across 15 different brain regions. Patients with OCD showed lower SERT binding potential in the brainstem (SMD = -1.13, 95% CI [-1.81 to -0.46]), midbrain (SMD = -0.54, 95% CI [-0.92 to -0.16]), and thalamus/hypothalamus regions (SMD = -0.58, 95% CI [-0.99 to -0.18]) with neglectable to moderate heterogeneity. By combining results from 2 decades of molecular imaging studies, we show that individuals with OCD exhibit lower SERT binding potential in specific brain regions, providing compelling evidence of a 5-HT system dysfunction. However, the exact mechanisms underlying this phenotype remain elusive. The limitations include heterogeneity across studies in populations, imaging techniques, and radiotracer usage.

Indexed as

BrainNeuroimagingObsessive-Compulsive DisorderReceptor, Serotonin, 5-HT2ASerotoninSerotonin Plasma Membrane Transport ProteinsHumansPositron-Emission TomographyTomography, Emission-Computed, Single-PhotonReceptor, Serotonin, 5-HT2ASerotoninSerotonin Plasma Membrane Transport Proteins5‐HT2A bindingmolecular imagingobsessionsserotoninSERT binding

Identifiers

PMID39511769
PMCPMC11789457

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.