A family study on first episode of psychosis patients: Exploring neuropsychological performance as an endophenotype

Abstract

Introduction Family studies provide a suitable approach to analyzing candidate endophenotypes of schizophrenia, including cognitive features. Objective To characterize different neurocognitive functions in a group of patients with first episode of psychosis (FEP), their first‐degree relatives (parents and siblings), and healthy controls (HC), in order to identify potential endophenotypes for schizophrenia spectrum disorders (SSD). Methods Participants were assessed in the context of a national project in Spain called PAFIP‐FAMILIAS. They completed the same neuropsychological battery, which included tests of verbal memory, visual memory, processing speed, working memory, executive functions, motor dexterity, attention, and theory of mind. Group comparisons were performed using one‐way ANOVA, followed by tests of multiple comparisons when appropriate. Results One hundred thirty‐three FEP patients were included, as well as 244 of their first‐degree relatives (146 parents and 98 siblings) and 202 HC. In general, relatives showed an intermediate performance between the HC and the FEP patients in all neurocognitive domains. However, the domains of executive functions and attention stood out, as relatives (especially parents) showed similar performance to FEP patients. This was replicated when selecting patients subsequently diagnosed with schizophrenia and their relatives. Conclusion These findings suggest that executive and attention dysfunctions might have a family aggregation and could be relevant cognitive endophenotypes for psychotic disorders. The study shows the potential of exploring intra‐family neuropsychological performance supporting neurobiological and genetic research in SSD.

Studying the relationship between intelligence quotient and schizophrenia polygenic scores in a family design with first-episode psychosis population

“…Siblings had similar IQs to controls, and their performance aligned with their family cognitive profile. Previous research consistently shows that siblings tend to perform better than the proband in cognitive domains such as executive functions and memory [ 6 , 32 , 45 – 47 ]. Siblings had higher educational attainment and lower cannabis use rates ( Table 1 ), which may be protective factors that increase cognitive reserve against psychosis [ 48 , 49 ].…”

“…The local institutional review committee (CEIm Cantabria) approved both projects (PAFIP and PAFIP-FAMILIES) under international research ethics standards and all participants gave their written informed consent. The initial sample consisted of 133 FEP patients, 146 parents, 98 siblings, and 202 controls [ 32 ].…”

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

“…Participants were recruited from two projects: (a) Program for Initial Phases of Psychosis (PAFIP; Pelayo-Terán et al, 2008) and (b) Program for Initial Phases of Psychosis and their relatives (PAFIP-FAMILIAS; Murillo-García et al, 2022), both from the University Hospital Marqués de Valdecilla (Cantabria, Spain). The total sample included 579 participants: 133 FEP patients, 146 parents, 98 siblings, and 202 HC groups.…”

“…The study's design cross sectionally assessed general cognitive performance and PS among FEP patients and their first-degree relatives from the PAFIP (Pelayo-Terán et al, 2008) and PAFIP-FAMILIAS projects (Murillo-García et al, 2022). All participants were informed about the characteristics of the study and signed the informed consent document showing their agreement to participate.…”

“…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.…”