The Portuguese version of the Personal and Social Performance Scale (PSP): reliability, validity, and relationship with cognitive measures in hospitalized and community schizophrenia patients
Deficits in social functioning are a core feature of schizophrenia and are influenced by both symptomatic and neurocognitive variables. In the present study we aimed to determine the reliability and validity of the Portuguese version of the Personal and Social Performance (PSP) scale, and possible correlations with measures of cognitive functioning. One-hundred and four community and inpatients with schizophrenia were assessed using measures of social functioning and symptom severity alongside measures of executive function, processing speed, and verbal memory. Convergent validity with the GAF in the four domains of the PSP varied from 0.357 to 0.899. Reliability was found to be satisfactory, with a Cronbach’s alpha coefficient of 0.789. Inter-rater reliability in the four domains of the PSP varied from 0.430 to 0.954. Low-functioning patients (PSP < 70) were older, had longer duration of illness, were more symptomatic and had worse cognitive performances, as compared with high-functioning patients (PSP ≥ 70). In a regression model, deficits in social functioning were strongly predicted both by symptomatic and neurocognitive variables; these together accounted for up to 62% of the variance. The present study supports the reliability and validity of the Portuguese language version of the PSP and further supports the original measure. The co-administration of brief cognitive assessments with measures of functioning may lead to more focused interventions, possibly improving outcomes in this group.