Frontal lobe functions in schizophrenia: Interest of the Stuss approach.

Objective: The term Executive Functions (EFs) refers to the higher-level skills we use every day to control and coordinate our cognitive abilities and behaviours. EFs are mainly supported by the frontal lobes and its connections. EFs are frequently impaired in schizophrenia, but the profiles of executive deficits accompanying schizophrenia remains unclear. The use of specific EFs models might help to shed new light on this issue. Stuss (Stuss & Alexander, 2007; Stuss, 2008, 2011, 2017) proposed an integrative and operant model of EFs which has never been used to explore and characterize deficits in schizophrenia. The aim of this study is to further examine EFs in schizophrenia in the light of the frontal lobe functional approach developed by Stuss (2008, 2011, 2017) in order to question EFs impairment homogeneity and heterogeneity in schizophrenia.

Methods: Forty-five patients with schizophrenia and fifty-five healthy controls were recruited. They all completed a series of neuropsychological tests selected and adapted to measure the five majors' functions of the frontal lobe described by Stuss (2017).

Results: Patients showed deficits in almost all the frontal functions. Inside each frontal lobe function, correlations were observed between all the corresponding measures. The study of profiles highlighted a heterogeneous functioning in schizophrenia.

Conclusions: The model of Stuss (Stuss & Alexander, 2007; Stuss, 2008, 2011, 2017) allows accurate and specific measures of the frontal functions and observation. Beyond "cold" or "hot" EFs division, this integrative approach is helpful to understand links within neurocognition.