Common gene expression profile for schizophrenia and bipolar disorder identified

Results of a study examining gene expression patterns in the brain suggest that the current categories of bipolar disorder and schizophrenia share a common gene expression profile, which has the potential to identify common pathophysiology and core treatments. Multiple genetic and environmental factors are thought to influence the respective aetiologies of schizophrenia and bipolar disorder. Traditionally, diagnosis of these disorders has relied on clinical examination of psychotic symptoms, with each disorder having a separate diagnostic classification. However, more recently attention has focused on the idea that schizophrenia and bipolar disorder are not separate illnesses and that they share many criteria differing along dimensions of psychosis and affective symptoms. The researchers proposed that the analysis of gene expression patterns in the brain has the potential to provide a ‘signature’ that is characteristic of each disorder. While similar studies have been conducted in the past, few have compared both disorders with a common reference control group. In the current study, RNA samples from the dorsolateral prefrontal cortex of individuals with schizophrenia (n=32), bipolar disorder (n=29) and control subjects (n=27) were tested. The effects of age, gender, and brain pH were controlled for in the analysis of differential gene expression by analysis of covariance (ANCOVA). The criteria for differential gene expression were: • that a gene was significantly dysregulated in both bipolar disorder and schizophrenia compared with the control subjects...