Relationship between grammar and schizophrenia: a systematic review and meta-analysis
Abstract Background Schizophrenia significantly impairs everyday communication, affecting education and employment. Such communication difficulties may arise from deficits in syntax—understanding and generating grammatical structures. Research on syntactic impairments in schizophrenia is underpowere...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-06-01
|
| Series: | Communications Medicine |
| Online Access: | https://doi.org/10.1038/s43856-025-00944-1 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850207100025700352 |
|---|---|
| author | Dalia Elleuch Yinhan Chen Qiang Luo Lena Palaniyappan |
| author_facet | Dalia Elleuch Yinhan Chen Qiang Luo Lena Palaniyappan |
| author_sort | Dalia Elleuch |
| collection | DOAJ |
| description | Abstract Background Schizophrenia significantly impairs everyday communication, affecting education and employment. Such communication difficulties may arise from deficits in syntax—understanding and generating grammatical structures. Research on syntactic impairments in schizophrenia is underpowered, with inconsistent findings, and it is unclear if deficits are specific to certain patient subgroups, regardless of symptom profiles, age, sex, or illness severity. Methods A pre-registered (Open Science Framework: https://doi.org/10.17605/OSF.IO/7FZUC ) search using PubMed, Scopus, PsycINFO, and Web of Science databases up to May 1, 2024, for all studies investigating syntax comprehension and production in schizophrenia vs. healthy controls. Excluding studies on those <18 years of age and qualitative research, we extracted Cohen’s d and log coefficient of variation ratio and used Bayesian meta-analysis across 6 domains: 2 in comprehension and 4 in production in patient-control comparisons. Study quality was evaluated using a modified Newcastle–Ottawa Scale, with moderators (age, sex, study quality, language) tested via meta-regression. Results We identify 86 relevant articles, of which 45 have sufficient data for meta-analysis (n = 2960 participants, 64.4% English, weighted mean age(sd) = 32.3(5.6)). Bayesian meta-analysis shows strong evidence of syntactic deficits in schizophrenia across all domains (d = 0.65–1.01, overall random-effects d = 0.86, 95% CrI [0.67–1.03]), with syntax comprehension being most affected, with weak publication bias. People with schizophrenia show increased variability in comprehension and production of long and complex utterances (lnCVR = 0.21, 95% CrI [0.07–0.36]), hinting at subgroups with differing performance. Conclusions Robust impairments in grammatical comprehension and production in schizophrenia suggest opportunities for targeted interventions focusing on syntax, a rule-based feature amenable to cognitive, educational, and linguistic interventions. |
| format | Article |
| id | doaj-art-9ae27e84cc98449494a571bc830e2444 |
| institution | OA Journals |
| issn | 2730-664X |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Communications Medicine |
| spelling | doaj-art-9ae27e84cc98449494a571bc830e24442025-08-20T02:10:38ZengNature PortfolioCommunications Medicine2730-664X2025-06-015111410.1038/s43856-025-00944-1Relationship between grammar and schizophrenia: a systematic review and meta-analysisDalia Elleuch0Yinhan Chen1Qiang Luo2Lena Palaniyappan3Higher School of Health Sciences and Techniques of Sfax, University of SfaxInstitute of Science and Technology for Brain-Inspired Intelligence, Research Institute of Intelligent Complex Systems, Fudan UniversityInstitute of Science and Technology for Brain-Inspired Intelligence, Research Institute of Intelligent Complex Systems, Fudan UniversityDouglas Mental Health University Institute, Department of Psychiatry, McGill UniversityAbstract Background Schizophrenia significantly impairs everyday communication, affecting education and employment. Such communication difficulties may arise from deficits in syntax—understanding and generating grammatical structures. Research on syntactic impairments in schizophrenia is underpowered, with inconsistent findings, and it is unclear if deficits are specific to certain patient subgroups, regardless of symptom profiles, age, sex, or illness severity. Methods A pre-registered (Open Science Framework: https://doi.org/10.17605/OSF.IO/7FZUC ) search using PubMed, Scopus, PsycINFO, and Web of Science databases up to May 1, 2024, for all studies investigating syntax comprehension and production in schizophrenia vs. healthy controls. Excluding studies on those <18 years of age and qualitative research, we extracted Cohen’s d and log coefficient of variation ratio and used Bayesian meta-analysis across 6 domains: 2 in comprehension and 4 in production in patient-control comparisons. Study quality was evaluated using a modified Newcastle–Ottawa Scale, with moderators (age, sex, study quality, language) tested via meta-regression. Results We identify 86 relevant articles, of which 45 have sufficient data for meta-analysis (n = 2960 participants, 64.4% English, weighted mean age(sd) = 32.3(5.6)). Bayesian meta-analysis shows strong evidence of syntactic deficits in schizophrenia across all domains (d = 0.65–1.01, overall random-effects d = 0.86, 95% CrI [0.67–1.03]), with syntax comprehension being most affected, with weak publication bias. People with schizophrenia show increased variability in comprehension and production of long and complex utterances (lnCVR = 0.21, 95% CrI [0.07–0.36]), hinting at subgroups with differing performance. Conclusions Robust impairments in grammatical comprehension and production in schizophrenia suggest opportunities for targeted interventions focusing on syntax, a rule-based feature amenable to cognitive, educational, and linguistic interventions.https://doi.org/10.1038/s43856-025-00944-1 |
| spellingShingle | Dalia Elleuch Yinhan Chen Qiang Luo Lena Palaniyappan Relationship between grammar and schizophrenia: a systematic review and meta-analysis Communications Medicine |
| title | Relationship between grammar and schizophrenia: a systematic review and meta-analysis |
| title_full | Relationship between grammar and schizophrenia: a systematic review and meta-analysis |
| title_fullStr | Relationship between grammar and schizophrenia: a systematic review and meta-analysis |
| title_full_unstemmed | Relationship between grammar and schizophrenia: a systematic review and meta-analysis |
| title_short | Relationship between grammar and schizophrenia: a systematic review and meta-analysis |
| title_sort | relationship between grammar and schizophrenia a systematic review and meta analysis |
| url | https://doi.org/10.1038/s43856-025-00944-1 |
| work_keys_str_mv | AT daliaelleuch relationshipbetweengrammarandschizophreniaasystematicreviewandmetaanalysis AT yinhanchen relationshipbetweengrammarandschizophreniaasystematicreviewandmetaanalysis AT qiangluo relationshipbetweengrammarandschizophreniaasystematicreviewandmetaanalysis AT lenapalaniyappan relationshipbetweengrammarandschizophreniaasystematicreviewandmetaanalysis |