Evidence map›Paper›PMID 33706323›Full record

SynthesisNeuropsychobiology2021

A Meta-Analysis of Brain-Derived Neurotrophic Factor Effects on Brain Volume in Schizophrenia: Genotype and Serum Levels.

Anthony O Ahmed, Samantha Kramer, Naama Hofman, John Flynn, Marie Hansen, Victoria Martin, Anilkumar Pillai, Peter F Buckley

Open access · hybridAbstract readMeta-AnalysisReview
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Neuropsychobiology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.

0numbers the graph read from it
0cells of the map it votes in
12citing papers in PubMed
1.9field-weighted citation impact, top 16% of its field
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

12 citing papers in PubMed, 23 citations in OpenAlex.

  1. Trial
  2. Article
  3. Frontiers in psychiatry · 2025
    Article
  4. Review
  5. Article
  6. Review
  7. BDNF and Cognitive Function in Chilean Schizophrenic Patients.International journal of molecular sciences · 2023
    Article
  8. Review
  9. Article
  10. Article
  11. Article
  12. 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 at 6 institutions in 1 country.

Anthony O AhmedDepartment of Psychiatry, Weill Cornell Medicine, White Plains, New York, USA, aoa9001@med.cornell.edu.
Samantha KramerDepartment of Psychology, Long Island University Post, New York, New York, USA.
Naama HofmanDepartment of Psychology, St. John's University, New York, New York, USA.
John FlynnDepartment of Psychology, Long Island University Brooklyn, New York, New York, USA.
Marie HansenDepartment of Psychology, Long Island University Brooklyn, New York, New York, USA.
Victoria MartinDepartment of Psychology, City University of New York, New York, New York, USA.
Anilkumar PillaiDepartment of Psychiatry and Health Behavior, Augusta University, Augusta, Georgia, USA.
Peter F BuckleyDepartment of Psychiatry, Virginia Commonwealth University, Richmond, Virginia, USA.
Long Island University · USAugusta University Health · USCity University of New York · USSt. John's University · USVirginia Commonwealth University · USWeill Cornell Medicine · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

aimThe Val66Met single-nucleotide polymorphism (SNP) on the BDNF gene has established pleiotropic effects on schizophrenia incidence and morphologic alterations in the illness. The effects of brain-derived neurotrophic factor (BDNF) on brain volume measurements are however mixed seeming to be less established for most brain regions. The current meta-analytic review examined (1) the association of the Val66Met SNP and brain volume alterations in schizophrenia by comparing Met allele carriers to Val/Val homozygotes and (2) the association of serum BDNF with brain volume measurements.

methodStudies included in the meta-analyses were identified through an electronic search of PubMed and PsycInfo (via EBSCO) for English language publications from January 2000 through December 2017. Included studies had conducted a genotyping procedure of Val66Met or obtained assays of serum BDNF and obtained brain volume data in patients with psychotic disorders. Nonhuman studies were excluded.

resultsStudy 1 which included 52 comparisons of Met carriers and Val/Val homozygotes found evidence of lower right and left hippocampal volumes among Met allele carriers with schizophrenia. Frontal measurements, while also lower among Met carriers, did not achieve statistical significance. Study 2 which included 7 examinations of the correlation between serum BDNF and brain volume found significant associations between serum BDNF levels and right and left hippocampal volume with lower BDNF corresponding to lower volumes. DISCUSSION: The meta-analyses provided evidence of associations between brain volume alterations in schizophrenia and variations on the Val66Met SNP and serum BDNF. Given the limited number of studies, it remains unclear if BDNF effects are global or regionally specific.

Indexed as

Brain-Derived Neurotrophic FactorSchizophreniaBrainGenotypeHippocampusHumansPolymorphism, Single NucleotideBrain-Derived Neurotrophic FactorBrain-derived neurotrophic factorBrain volumers6265SchizophreniaVal66Met

Identifiers

PMID33706323
PMCPMC8619762
OpenAlexW3134098232

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.