Abstract: The present application provides antioxidant substances having enediol structure that can prevent the decomposition of biopyrrin. Agents for preventing decomposition of biopyrrin include an antioxidant substance having enediol structure, or a salt, an ester or a glycoside thereof, or a solvate, a stereoisomer or a tautomer thereof. In a biological sample to which the agent for preventing decomposition of the invention is added, the decomposition of biopyrrin can be prevented at ambient temperature or lower for a long term.

Abstract: Provided is a biomarker for diagnosing at-risk mental state (ARMS) that may include one or more selected from the group consisting of biopyrrin, cortisol, a KFLC or a fragment thereof, and a AFLC or a fragment thereof. Further provided is an ARMS diagnosis of a subject that may be performed quickly, easily, and accurately by measuring the amount of the biomarker for diagnosing ARMS in a biological sample.

Abstract: The purpose of the present invention is to provide: a biomarker for psychiatric and neurological disorders, in particular, a biomarker for diagnosing psychiatric and neurological disorders; and a test kit and test method for psychiatric and neurological disorders. The inventors discovered that there is a significant increase in the concentration of free ? immunoglobulin chains and free ? immunoglobulin chains in the blood samples from patients with psychiatric and neurological disorders. Consequently, the present invention provides a biomarker for psychiatric and neurological disorders that includes at least one selected from the group consisting of free ? immunoglobulin chains, free ? immunoglobulin chains, and fragments thereof. Using this biomarker for psychiatric and neurological disorders enables the psychiatric and neurological disorders to be easily tested and diagnosed with the blood samples from the subjects.

Abstract: The purpose of the present invention is to provide: a biomarker for psychiatric and neurological disorders, in particular, a biomarker for diagnosing psychiatric and neurological disorders; and a test kit and test method for psychiatric and neurological disorders. The inventors discovered that there is a significant increase in the concentration of free ? immunoglobulin chains and free ? immunoglobulin chains in the blood samples from patients with psychiatric and neurological disorders. Consequently, the present invention provides a biomarker for psychiatric and neurological disorders that includes at least one selected from the group consisting of free ? immunoglobulin chains, free ? immunoglobulin chains, and fragments thereof. Using this biomarker for psychiatric and neurological disorders enables the psychiatric and neurological disorders to be easily tested and diagnosed with the blood samples from the subjects.

Abstract: The purpose of the present invention is to provide: a biomarker for psychiatric and neurological disorders, in particular, a biomarker for diagnosing psychiatric and neurological disorders; and a test kit and test method for psychiatric and neurological disorders. The inventors discovered that there is a significant increase in the concentration of free ? immunoglobulin chains and free ? immunoglobulin chains in the blood samples from patients with psychiatric and neurological disorders. Consequently, the present invention provides a biomarker for psychiatric and neurological disorders that includes at least one selected from the group consisting of free ? immunoglobulin chains, free ? immunoglobulin chains, and fragments thereof. Using this biomarker for psychiatric and neurological disorders enables the psychiatric and neurological disorders to be easily tested and diagnosed with the blood samples from the subjects.