Reduced early teenage premorbid functioning in schizophrenia
MedWire News: Children who go on to develop schizophrenia in adulthood have poorer premorbid nonacademic performance and show poorer behavioural ratings compared with their peers who remain mentally healthy, Israeli researchers report.
Furthermore, such children show poorer premorbid nonacademic performance and behavioral ratings than those who go on to develop affective disorders in adulthood.
Writing in Schizophrenia Research, Jonathan Rabinowitz (Bar Ilan University, Ramat Gan, Israel) and team explain that "historically, premorbid deficits have been observed in many persons prior to a formal diagnosis of psychosis."
But they observe that most of these studies were conducted in late adolescence and focused IQ test scores.
Furthermore, "few studies have aimed to differentiate between premorbid functioning of persons with affective disorders and schizophrenia," they add.
To address these issues, the team studied school report data on 21,448 children aged 13-14 years (8th grade) collected over a 10-year period between 1978 and 1988.
The school reports included assessments of academic performance derived from grades in Hebrew, math, science, English, Arabic, and grammar, nonacademic performance derived from grades in physical education, music, arts and drawing, and handcraft, and teacher ratings of behavior in the classroom.
A search of the National Psychiatric Hospitalization Case Registry of the State of Israel identified 194 children who went on to develop schizophrenia, and 41 who went on to develop affective disorders in adulthood.
After accounting for gender and school, the researchers found that children who later developed schizophrenia had significantly poorer 8th grade behavioral ratings and nonacademic performance compared with children who remained mentally healthy in adulthood, at effect sizes of -0.20 and -0.18, respectively. However, there was no significant difference between these groups regarding academic performance.
Furthermore, children who later developed schizophrenia had poorer nonacademic performance and behavioral ratings than those who subsequently developed affective disorders, but the differences were nonsignificant.
In addition, Cox regression modeling showed that poorer nonacademic performance and behavioral ratings were significantly associated with earlier age of first hospitalization for schizophrenia.
Rabinowitz and team conclude: "The current study uniquely contributes to the literature by highlighting that early deficits specific to schizophrenia are identifiable from teacher ratings and nonacademic performance at the age of 13 to 14, prior to first hospitalization, before symptoms are manifest."
They add that "the current results uniquely extend prior research by suggesting that deficits in schizophrenia are more pronounced than in affective disorders at an earlier age than previously documented."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Mark Cowen