Language, executive functioning and symptomatology—Is fluency a transversal tool in schizophrenia?

Despite a large number of studies on fluency disorders in schizophrenia, it is still not clear whether executive functioning and fluency tasks are empirically linked and how symptomatology could specifically get involved on these influences. We carried out analyses of performances in several verbal fluency tasks, a non-verbal fluency task and an executive test (FAB) in 25 schizophrenics and 25 healthy subjects matched in terms demographic data. Patients also completed the Positive and Negative Symptoms Scale in order to control for their clinical profile. Our results suggest that schizophrenic patients show both category and letter fluency deficits with a greater impairment for letter fluency. They also display poorer performances for the non-verbal fluency task. In patients, all the verbal and non-verbal fluencies are significantly correlated with the FAB total score. By contrast, in controls, only letter fluency correlates with the FAB total score, which is congruent with previous literature on the healthy mechanisms of verbal fluency. Besides, factorial analyses show that symptomatology is specifically related to particular indexes of fluency tasks. Taken together, these data lead to support the hypothesis of retrieval rather than semantic difficulties and alargest involvement of executive functioning in schizophrenics during tasks that require a certain degree of efficiency, with performance being influenced by the clinical profile. Yet, the relation between fluency scores and executive functioning has to be more intensively explored and further studies should include semantic memory measures that fit with pathology’s constraints and characteristics.