P.1.j.025 Abnormal cognitive salience but not WCST scores are associated with poor outcome in patients with schizophrenia

Abstract

Purpose of study: Psychopathology and cognitive impairment are poor predictors of functional outcome in patients with schizophrenia. In contrast, recent data have demonstrated that dopamineassociated functions such as baseline motivational deficits and social cognition are more relevant to predict patient functionality. Social cognition is a complex entity that includes several information processes such as reasoning, attention and memory, all involved in social adjustment. These cognitive dimensions are known to be particularly impaired in schizophrenia patients. Among several components, it comprises cognitive salience, a measure of the aberrant dopamine signalling in brain. In the present study, functional outcome was correlated to (i) psychopathology, (ii) attention and frontal lobe executive function, and (iii) cognitive salience in a population of stabilised patients with schizophrenia (SCZ). Method: Chronic medicated patients with schizophrenia (n = 35) have been examined and compared to a healthy control population (n = 34). Clinical characteristics, prefrontal functioning, and cognitive salience were assessed using PANSS (Positive and Negative Syndrome Scale), CGI (Clinical Global Impression), WCST (Wisconsin Card Sorting Test), SAT, and CPTAX tests respectively. CPT-AX (Continuous Performance Test-AX version) and SAT (Salience Attribution Test) are two standardised and computerised tests to study cognitive salience. SAT: is a probabilistic reward learning game that employs cues that vary across task-relevant and task-irrelevant dimensions; it provides behavioural indices of adaptive and aberrant reward teaching. CPT-AX with salient stimuli doesn’t use words but colour stimuli and assesses working memory by varying inter stimulus interval. Global Assessment of functioning (GAF) evaluated the overall functioning of patients. Results: Compared to control subjects, 60% of SCZ patients showed a significant decrease in performance for WSCT (perseverative responses, perseverative and non-perseverative errors, and errors). SAT (Explicit Adaptive Salience) values were significantly different for 42% of subjects, while CPT-AX scores (Hit-score, False Alarm Rate, Response Time) were abnormal in only 27% of patients. Only the latter subgroup had abnormal scores in WSCT showing a possible participation of prefrontal involvement in this salience test. Interestingly and in accordance with data of literature, abnormal responses to WCST did not predict low GAF score in our study. In contrast, subjects with low SAT scores and CPT-AX separately were significantly (p< 0.05) more frequent in the group of patients with low GAF scores. We also tested the hypothesis that the CPTAX and SAT evaluate two different dimensions of salience. We reviewed patients with low scores on both SAT and CPT-AX. This subpopulation had indeed scores significantly (p = 0.02) lower in the GAF compared to patients without this combination. Conclusion: Alteration of the cognitive salience tests CPTAX and SAT is associated with functional outcome impairment in patients with schizophrenia. Preliminary data are indicating that these two tests can describe the activity of two separated neurobiological networks involved in cognitive salience.