Grammatical impairment in schizophrenia: An exploratory study of the pronominal and sentential domains

PLoS One. 2023 Sep 12;18(9):e0291446. doi: 10.1371/journal.pone.0291446. eCollection 2023.

Abstract

Schizophrenia (SZ) is a severe mental disorder associated with a variety of linguistic deficits, and recently it has been suggested that these deficits are caused by an underlying impairment in the ability to build complex syntactic structures and complex semantic relations. Aiming at contributing to determining the specific linguistic profile of SZ, we investigated the usage of pronominal subjects and sentence types in two corpora of oral dream and waking reports produced by speakers with SZ and participants without SZ (NSZ), both native speakers of Brazilian Portuguese. Narratives of 40 adult participants (20 SZ, and 20 NSZ-sample 1), and narratives of 31 teenage participants (11 SZ undergoing first psychotic episode, and 20 NSZ-sample 2) were annotated and statistically analyzed. Overall, narratives of speakers with SZ presented significantly higher rates of matrix sentences, null pronouns-particularly null 3Person referential pronouns-and lower rates of non-anomalous truncated sentences. The high rate of matrix sentences correlated significantly with the total PANSS scores, suggesting an association between the overuse of simple sentences and SZ symptoms in general. In contrast, the high rate of null pronouns correlated significantly with positive PANSS scores, suggesting an association between the overuse of null pronominal forms and the positive symptoms of SZ. Finally, a cross-group analysis between samples 1 and 2 indicated a higher degree of grammatical impairment in speakers with multiple psychotic episodes. Altogether, the results strengthen the notion that deficits at the pronominal and sentential levels constitute a cross-cultural linguistic marker of SZ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Brazil
  • Humans
  • Linguistics
  • Psychotic Disorders*
  • Schizophrenia*
  • Semantics

Grants and funding

MCF: Research fellowships from the Brazilian Coordination for the Improvement of Higher Education Personal (Capes) and the Brazilian National Council for Scientific and Technological Development (CNPq) CR: The Brazilian National Council for Scientific and Technological Development (CNPq) Humanities. Grant number: 439434/ 2018-1. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.