Small Words That Matter: Linguistic Style and Conceptual Disorganization in Untreated First-Episode Schizophrenia

Angelica Silva; Roberto Limongi; Michael MacKinley; Lena Palaniyappan

doi:10.1093/schizbullopen/sgab010

Small Words That Matter: Linguistic Style and Conceptual Disorganization in Untreated First-Episode Schizophrenia

Schizophr Bull Open. 2021 Mar 15;2(1):sgab010. doi: 10.1093/schizbullopen/sgab010. eCollection 2021 Jan.

Authors

Angelica Silva¹, Roberto Limongi^{1

2}, Michael MacKinley^{1

2

3}, Lena Palaniyappan^{1

2

3

4

5}

Affiliations

¹ Robarts Research Institute, London, ON, Canada.
² Department of Psychiatry, University of Western Ontario, London, ON, Canada.
³ Lawson Health Research Institute, London, ON, Canada.
⁴ Department of Medical Biophysics, University of Western Ontario, London, ON, Canada.
⁵ The Brain and Mind Institute, University of Western Ontario, London, ON, Canada.

Abstract

This study aimed to shed light on the linguistic style affecting the communication discourse in first-episode schizophrenia (FES) by investigating the analytic thinking index in relation to clinical scores of conceptual and thought disorganization (Positive and Negative Syndrome Scale, PANSS-P2 and Thought and Language Index, TLI). Using robust Bayesian modeling, we report three major findings: (1) FES subjects showed reduced analytic thinking, exhibiting a less categorical linguistic style than healthy control (HC) subjects (Bayes factor, BF₁₀ > 1000), despite using the same proportion of function and content words as HCs; (2) the lower the analytic thinking score, the higher the symptoms scores of conceptual disorganization (PANSS-P2, BF = 22.66) and global disorganization of thinking (TLI, BF₁₀ = 112.73); (3) the linguistic style is a better predictor of conceptual disorganization than the cognitive measure of processing speed in schizophrenia (SZ). These findings provide an objectively detectable linguistic style with a focus on Natural Language Processing Analytics of transcribed speech samples of patients with SZ that require no clinical judgment. These findings also offer a crucial insight into the primacy of linguistic structural disruption in clinically ascertained disorganized thinking in SZ. Our work contributes to an emerging body of literature on the psychopathology of SZ using a first-order lexeme-level analysis and a hypothesis-driven approach. At a utilitarian level, this has implications for improving educational and social outcomes in patients with SZ.

Keywords: first-episode schizophrenia; formal thought disorder; linguistic style; natural language processing analytics; speech–language impairment.