Real-world premorbid functioning in schizophrenia and affective disorders during the early teenage years: A population-based study of school grades and teacher ratings Vardit Zerem Ullman a, b , Stephen Z. Levine a , Abraham Reichenberg c , Jonathan Rabinowitz a, ⁎ a Bar Ilan University, Ramat Gan, Israel b Ashkelon Academic College, Israel c Department of Psychosis Studies, Institute of Psychiatry, King's College London, UK abstract article info Article history: Received 4 July 2011 Received in revised form 5 January 2012 Accepted 17 January 2012 Available online 11 February 2012 Keywords: Premorbid Schizophrenia Functioning Registry Population Epidemiology Background: Population-based studies of cognitive and behavioral premorbid functioning in psychotic disor- ders 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 Hospitaliza- tion 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 perfor- mance (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 sig- nificantly 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. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Historically, premorbid deficits have been observed in many per- sons prior to a formal diagnosis of psychosis (e.g., Kraepelin, 1919; Bleuler, 1950). These early clinical observations have received empir- ical support over the last decade (Maccabe, 2008). Meta-analysis has shown that prior to the onset of schizophrenia, IQ scores are ap- proximately half a standard deviation below that of healthy controls (Woodberry et al., 2008). Research with epidemiological population- based cohorts has used a historical prospective design to link standard- ized IQ tests administered nationally as part of draft board screening in Israel (e.g., Davidson et al., 1999; Rabinowitz et al., 2005) and Sweden (David et al., 1997) to psychiatric hospitalization registries. These studies have shown that premorbid IQ (a) is lower in people later hospitalized with schizophrenia compared with controls; and (b) is moderately related to increased risk for schizophrenia and (c) is associ- ated with subsequent poorer hospitalization outcomes. For instance, in an Israeli study, risk for schizophrenia spectrum disorders increased with lower IQ scores (Reichenberg et al., 2006). Prior research, however, acknowledges the limitation that it is unascertainable as to whether or not cases were premorbid or in the prodromal stage of illness. This high- lights that more population-based research, like previous reports of pre-schizophrenia IQ deficits during childhood (Cannon et al., 2000), is required to extend the period from assessment to the onset of illness, by using data from an earlier age. This helps ensure that the assessment was done premorbidly and examines the extent of premorbid deficits at a younger age (for a review of studies of earlier ages see: Maccabe, 2008; Woodberry et al., 2008; Khandaker et al., 2011). Unlike research with the large population-based cohorts using a historical prospective design, that was mostly undertaken in Israel and Sweden with standardized tests during late adolescence, research with school grades in early adolescence has produced less clear-cut findings (MacCabe et al., 2008). Premorbid academic deficits in native language and math have, however, been observed during the early Schizophrenia Research 136 (2012) 13–18 ⁎ Corresponding author. E-mail address: jr827@columbia.edu (J. Rabinowitz). 0920-9964/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.schres.2012.01.021 Contents lists available at SciVerse ScienceDirect Schizophrenia Research journal homepage: www.elsevier.com/locate/schres