Lack of association between neuropsychological performance and level of psychosis-proneness in an adolescent psychiatric sample.

Studies of the prodromal stage of schizophrenia show that the late prepsychotic phase is associated with mild neuropsychological deficits that parallel those of schizophrenia. However, it is still unclear whether this association is present across the whole range of symptoms of psychosis-proneness, or specific to the extreme groups. In this study, the linear associations between dimensions of psychosis-proneness (as measured by the 92-item Prodromal Questionnaire) and performance on 20 neuropsychological measures were assessed in a group of 71 nonpsychotic adolescent psychiatric patients. A structure of positive, negative and disorganized prodromal symptom dimensions was found, replicating earlier findings. No symptom dimension was significantly associated with neuropsychological performance, even when corrected for nonspecific psychological distress. These findings suggest that the association between symptoms and neuropsychological performance is specific to high levels of symptoms or to the truly prodromal subpopulation. The results also highlight the importance of simultaneous assessment of affective state.