Executive function processes mediate the impact of working memory impairment on intelligence in schizophrenia

ObjectiveThe study investigated working memory, executive functions (conceptualized as response inhibition, updating, and shifting), and intelligence in schizophrenia, using structural equation modelling to determine the relationship between working memory and intelligence, testing whether specific executive functions act as a mediator for the association.MethodOne hundred and twenty-five individuals diagnosed with schizophrenia and 64 healthy participants were included in the study, tested using measures of working memory, intelligence and executive functioning. Structural equation modelling (SEM) was used to estimate direct and indirect associations between main measures.ResultsThe schizophrenia group had significantly lower working memory, executive function and intelligence than the healthy group. The relationship between working memory and intelligence was significantly mediated by inhibition, updating and shifting functions.ConclusionThe study indicates a mediating role of executive functions in determining the association between working memory and intellectual function in schizophrenia. It is further proposed that in people with schizophrenia, cognitive remediation approaches targeting working memory through executive functioning may in turn improve intellectual function generally.