Co-aggregation of cognitive, personality and genetic risk indicators of schizophrenia in an ongoing Catalan family study

Abstract

Background

Neurocognitive deficits and schizotypal features are elevated in first-degree relatives of schizophrenia patients. However, the co-aggregation of these indicators is not well known. Some studies have found that neurocognitive deficits and schizotypy increase in severity with the density of family history of schizophrenia. Therefore, we studied in affected families a) whether the status of Presumed Carrier (PC) of the genetic risk for schizophrenia is associated with higher levels of neurocognitive deficits and schizotypic features and b) the relationship between schizotypy and neurocognition.

Methods

From an ongoing Catalan Multicentric Family Study on Schizophrenia, 70 families were included in this analysis. 90 non-psychotic parents of schizophrenic patients (age 50.7/8.8; education 10.3/4.04; IQ 96.2/14.6) were defined as PC if they had at least one first (apart of offspring) or second degree relative with schizophrenia spectrum disorders (FIGS), resulting in 17 PC and 73 non-PC. Schizotypic features were assessed with the SCID-II and the SPQ-B. Working memory (WM), executive functioning, sustained attention, verbal fluency and logical memory were also assessed.

Results

PC differed significantly from NPC on verbal working memory, even after controlling for IQ (d=0.8). They did not differ on any of the self-reported or interview measures of schizotypy. The negative schizotypic dimension was associated with more WCST-perseverative errors, and low scores in spatial-WM, verbal fluency and immediate/delayed logical memory.

Discussion

A large association was found between verbal-WM and the familial background of schizophrenia. Only negative features were associated with some neurocognitive functions, supporting the view of multiple independent dimensions or a pleiotropic expression of risk.