Cognitive correlates of semantic language disorder in first-episode schizophrenia

Abstract

Introduction: Language disorder in schizophrenia is commonly measured using instruments such as the Thought, Language and Communicative disorder rating scale (TLC). However, the TLC score represent an aggregate measure of abnormalities at different linguistic levels. The Clinical Language Disorder Rating Scale (CLANG) was developed (Chen et al., 1996) based on psycholinguistic levels. Factor analysis yielded three distinct levels of abnormalities: semantic, poverty and general. The diagnostic significance for CLANG has been suggested (Ceccherini-Nelli and Crow, 2003). The present study aimed to explore the relationship between language disorder and cognition in a sample of first episode schizophrenic patients. Methods: 45 first-episode schizophrenic patients (DSM-IV) in Hong Kong, were recruited at the time of their illness presentation (drug naïve). The mean age was 25 sd 8.9), mean education was 11.4 years (sd 2.57). Cognitive measures included IQ, verbal fluency, letter number span, visual production, stroop, logical memory, trail making, six element test and Wisconsin Card Sorting Test (WCST). Results: Stepwise linear regression analyses were computed for each of the CLANG dimensions. “Semantic” dysfunctions are associated with trail making B (p<0.001), WCST perseverative response (p=0.009) and Hayling completion test error (p=0.019), with an r-square of 0.514. “poverty” was significantly associated with Hayling completion test error (p<0.001), WCST perseverative response (p=0.01) and Stroop word error (p=0.013) with an r-square of 0.478. The CLANG “general” was associated only with the trail making version B (p=0.01) with an r-square of 0.12. Conclusion Using the CLANG we captured different dimensions of language disorganization. We demonstrated each of these dimensions have distinctive cognitive correlates. Reference Ceccherini-Nelli, Alfonso. Crow, Timothy J. (2003) Disintegration of the components of language as the path to a revision of Bleuler’s and Schneider’s concepts of schizophrenia. Linguistic disturbances compared with first-rank symptoms in acute psychosis. British Journal of Psychiatry. 182:233-40 Chen EYH, Lam, LCW, Kan CS, Chan CKY, Kwok CL, Nguyen DGH, Chen RYL (1996) Language disorganization in schizophrenia: validation and assessment with a new clinical rating instrument. The Hong Kong Journal of Psychiatry, 6(1), 4-13.