Aberrant salience consists of the unusual or incorrect assignment of salience, significance or value to different innocuous stimuli. It has been hypothesized that subjects with an aberrant salience could be proneness to develop psychosis. Despite the importance of this concept in psychosis, only few instruments assess aberrant salience.

To evaluate aberrant salience processing in a clinical trans-diagnostic sample and its relationship with psychotic symptoms.

Thirty-six outpatient subjects attending the Psychiatric Unit of the University of Florence were recruited: 9 with Major Depression Disease (MDD), 8 with Schizophrenia (SC), 19 with Bipolar Disorder (BD). Patients were assessed by means of a clinical interview (SCID-I/P) and several questionnaires, including the Aberrant Salience Inventory (ASI).

The three groups showed significant differences in the lifetime presence of psychotic symptoms, with higher frequency in BD and SC patients (p< 0.01). Significant differences in ASI scores were found between MDD and BD (p< 0.01), and SC and BD (p< 0.01), while any difference between BD and SC was observed. Subjects with positive ASI (cut-off>14) reported more frequently past and lifetime psychotic symptoms (p< 0.01) and constituted a distinct cluster from patients with ASI score < 14.

Aberrant salience is significantly associated to lifetime psychotic symptoms. Thus it represents a relevant psychopathologic dimension that requires a careful investigation in patients with an history of psychotic events. The ASI could represent an useful instrument to evaluate the proneness of clinical and pre-clinical samples to develop psychotic symptoms.