Cognitive profiles of healthy siblings of first‐episode schizophrenia patients

Abstract

Aim: Cognitive deficit in psychotic illness is intensively studied, different cognitive subtypes have been suggested. In recent years, there has been an increase in the number of studies in patients with schizophrenia and their relatives searching for endophenotypes of the disease. The aim of our study was to investigate cognitive performance and cognitive subtypes in the siblings of the patients.Methods: Four groups of subjects were included: patients with a first episode of psychotic illness, the siblings of these patients, and two control groups. All the study subjects (N = 84) had a battery of neuropsychological tests that measured basic cognitive domainsmemory, executive functions, attention, visual-spatial skills, language skills and psychomotor speedadministered to them. The data were assessed with pairwise t-tests for group comparisons. The siblings were distributed into three groups according to their cognitive performance: non-deficit, partial deficit, and global deficit. Subsequently, the patients were assigned into three groups corresponding to their siblings' performance.Results: Our results revealed attenuation of abstract thinking in the siblings compared to the controls. As expected, the patients showed impairment across all cognitive domains. The patients and siblings demonstrated similar profiles in each subtype, in the severity of their impairment, and in their patterns of cognitive performance. Conclusions:Our results suggest that the cognitive profile can be considered as an endophenotype of psychotic disorders.

Processing speed in first episode of psychosis and first-degree relatives: A candidate endophenotype of spectrum schizophrenia disorders.

“…Criterion (e), impairment in affected and unaffected family members at a higher level than in the general population, is partially fulfilled. Several studies support that our data reveal a lower performance in PS among unaffected first-degree relatives compared with HC (Chu et al, 2019; Erzin et al, 2021; Feng et al, 2020; Valerio et al, 2021; Van Os et al, 2020; Voráčková et al, 2021). Last, the criterion (f), to be a reliably measurable trait that is more strongly associated with the specific disease of interest than with other psychiatric conditions, is partially fulfilled.…”

“…Concerning criterion (b), the presence of a deficit in PS among firstdegree relatives reinforces the potential genetic association between cognitive deficits and familial heritability, as supported by the existing literature (Lichtenstein et al, 2009;Sullivan et al, 2003;Toulopoulou et al, 2007). Furthermore, our results showed that first-degree relatives are situated in an intermediate performance on PS between FEP patients and HC (Chu et al, 2019;Erzin et al, 2021;Feng et al, 2020;Valerio et al, 2021;Van Os et al, 2020;Voráčková et al, 2021). Regarding criterion (c), state independence, the cross-sectional nature of our study did not allow us to explore this circumstance.…”

“…DSCT has been suggested as a screening tool in FEP (August et al, 2012). FEP patients have consistently shown poor performance on the DSCT (Andersen et al, 2013; Ayesa-Arriola et al, 2016; González-Blanch et al, 2011; Mesholam-Gately et al, 2009; Pelayo-Terán et al, 2008; Rodriguez et al, 2019), as well as have their first-degree relatives (Bora, 2017; Chu et al, 2019; Glahn et al, 2007; Hou et al, 2016; Murillo-García et al, 2022; Voráčková et al, 2021), indicating a relationship between PS deficits and familial kinship. The presence of PS impairments in both patients and their relatives suggests a potential genetic risk factor for PS deficits and highlights the possibility of PS as an endophenotype of SSDs.…”

Koncepcja endofenotypu w badaniach porównawczych zaburzeń funkcji poznawczych osób chorujących na schizofrenię i ich zdrowego rodzeństwa. Przegląd piśmiennictwa z lat 2010–2020

“…Zgodnie z oczekiwaniami pacjenci wykazywali zaburzenia we wszystkich domenach poznawczych. Pacjenci i rodzeństwo wykazywali podobny profil w każdym z podtypów, w nasileniu upośledzenia i wzorcach funkcjonowania poznawczego [17]. Drugie z badań z 2020 roku dotyka zaburzeń funkcji poznawczych osób, które przebyły pierwszy epizod schizofrenii oraz ich zdrowego rodzeństwa w kontekście poznania społecznego, o czym poniżej [18].…”

Impact of cognitive performance and negative symptoms on psychosocial functioning in Czech schizophrenia patients

“…Various works on this topic have confirmed that more than 80% of patients with schizophrenia suffer from various degrees of cognitive deficit, which markedly influence daily functioning 14 , 16 – 18 . Cognitive impairment can be detected before the appearance of first-episode symptoms (at prodromal state) and to some extent also in the first degree of healthy relatives 27 , 28 . A deficit of cognitive performance can be found in several neurocognitive domains and also in social cognition in schizophrenia patients 14 .…”