<P>PROBLEM TO BE SOLVED: To provide a method for examining schizophrenia, a reagent or an apparatus for examining schizophrenia, which is useful in the method and a therapeutic agent or an ameliorant for schizophrenia, effective for treating or ameliorating schizophrenia. <P>SOLUTION: Schizophrenia is diagnosed in a subject through a process for assaying at least one selected from the group consisting of (1) gene abnormality of glyoxylase I gene, (2) an expression amount or activity of glyoxylase I in a biological sample, (3) an amount of a carbonyl compound or its protein-modified product and (4) an amount of pyridoxal in a biological sample. The therapeutic agent or ameliorant for schizophrenia comprises a carbonyl scavenger or a carbonyl protein modification product formation inhibitor as an active ingredient. <P>COPYRIGHT: (C)2009,JPO&INPIT 
EXAMINATION AND TREATMENT OF SCHIZOPHRENIA