Real-world premorbid functioning in schizophrenia and affective disorders during the early teenage years: a population-based study of school grades and teacher ratings.

BACKGROUND Population-based studies of cognitive and behavioral premorbid functioning in psychotic disorders generally focus on late adolescence in schizophrenia and most are based on IQ test scores. AIMS To examine differences in school grades at the ages of 13-14 between persons hospitalized during adulthood for schizophrenia or affective disorders and their peers. METHODS Ten years of school report data were ascertained on 8th grade children (n=21,448) in the city of Jerusalem (1978-1988). During adulthood cases with schizophrenia (n=194, 0.9%) or an affective disorder (n=41, 0.19%) were identified based on psychiatric hospitalizations in the National Psychiatric Hospitalization Case Registry of the State of Israel. School assessments of academic performance, nonacademic topics, and teacher ratings of classroom behavior were compared between peers without illness and cases, and their association with illness was examined. RESULTS Children subsequently hospitalized with schizophrenia had significantly lower nonacademic performance (ES=.20, p=.007) and teacher ratings on behavior (ES=.18, p=.02) than controls and numerically lower teacher behavior ratings than people subsequently hospitalized for an affective disorder (ES=.25, p=.19). Cox regression modeling showed that poorer nonacademic and lower behavioral ratings were significantly associated with earlier age of onset of schizophrenia. CONCLUSIONS Premorbid behavior and nonacademic deficits are evident in early adolescence among persons subsequently hospitalized with schizophrenia and different from those hospitalized with affective disorders. This suggests that these ratings may have diagnostic specificity between schizophrenia and affective disorders.