Impaired sustained and selective attention have been seen as vulnerability factors to psychotic disorders. Relatives of psychotic patients are a risk population for psychosis, and previous studies have shown that they displayed more attentional deficits compared with healthy controls. Additionally, relatives have more pathological personality and schizotypy, the least considered also to be the expression of the genetic vulnerability to schizophrenia. There are few studies that relate attention to personality factors in relatives of psychotic patients.

To compare attentional performance of siblings of psychotic patients with those of healthy controls, taking into account their pathological and schizotypal personality.

The Spanish version of the SPQ and the DAPP-BQ were administered to a sample of 51 subjects that were divided into four groups by a hierarchical cluster analysis: siblings with high pathological personality (SHPP), siblings with low pathological personality (SLPP), controls with high pathological personality (CHPP), and controls with low pathological personality (CLPP). In all the subjects we assessed a sustained attention index (SUA) and a selective attention index (SEA). We compared the performance of the four groups on these attentional indexes.

We found that SHPP had worse performance on sustained attention compared with CLPP. Specifically this difference was in the reaction time item of the SUA.

The high schizotypy and pathological personality had an influence on sustained attentional performance in the siblings of patients with psychosis, but not in the healthy controls.