Analyzing language ability in first-episode psychosis and their unaffected siblings: A diffusion tensor imaging tract-based spatial statistics analysis study

• Published in: Journal of psychiatric research 2024-11, Vol.179, p.229-237
• Main Authors: Çabuk, Tuğçe, Şahin Çevik, Didenur, Çakmak, Işık Batuhan, Yılmaz Kafalı, Helin, Şenol, Bedirhan, Avcı, Hanife, Karlı Oğuz, Kader, Toulopoulou, Timothea
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Brain - diagnostic imaging; Brain - pathology; Brain - physiopathology; Diffusion Tensor Imaging; Female; First-episode psychosis; Formal thought disorder; Humans; Language; Language Disorders - diagnostic imaging; Language Disorders - etiology; Language Disorders - physiopathology; Male; Psychotic Disorders - diagnostic imaging; Psychotic Disorders - physiopathology; Schizophrenia; Schizophrenia - diagnostic imaging; Schizophrenia - physiopathology; Sibling; Siblings; White Matter - diagnostic imaging; White Matter - pathology; Young Adult
• ISSN: 0022-3956; 1879-1379; 1879-1379
• DOI: 10.1016/j.jpsychires.2024.09.021

Schizophrenia (SZ) is a highly heritable mental disorder, and language dysfunctions play a crucial role in diagnosing it. Although language-related symptoms such as disorganized speech were predicted by the polygenic risk for SZ which emphasized the common genetic liability for the disease, few studies investigated possible white matter integrity abnormalities in the language-related tracts in those at familial high-risk for SZ. Also, their results are not consistent. In this current study, we examined possible aberrations in language-related white matter tracts in patients with first-episode psychosis (FEP, N = 20), their siblings (SIB, N = 20), and healthy controls (CON, N = 20) by applying whole-brain Tract-Based Spatial Statistics and region-of-interest analyses. We also assessed language ability by Thought and Language Index (TLI) using Thematic Apperception Test (TAT) pictures and verbal fluency to see whether the scores of these language tests would predict the differences in these tracts. We found significant alterations in language-related tracts such as inferior longitudinal fasciculus (ILF) and uncinate fasciculus (UF) among three groups and between SIB and CON. We also proved partly their relationship with the language test as indicated by the significant correlation detected between TLI Impoverished thought/language sub-scale and ILF. We could not find any difference between FEP and CON. These results showed that the abnormalities, especially in the ILF and UF, could be important pathophysiological vulnerability indexes of schizophrenia. Further studies are required to understand better the role of language as a possible endophenotype in schizophrenia with larger samples. •Schizophrenia is a heritable mental disorder and language plays a crucial role in diagnosing it.•We still do not know whether language is a trait- or state-marker in psychosis.•Diffusion tensor imaging and language tests were applied to psychosis patients and their siblings.•The white matter in language-related tracts were different between siblings of patients and controls.