Abstract: The present invention aims to provide methods to detect cognitive impairment including mild cognitive impairment and Alzheimer disease by using a protein or its partial peptide that differs in presence or absence, or in quantity between non-cognitive impairment and patients with cognitive impairment and further aims to present biomarkers comprising said protein and said partial peptide to be used to detect cognitive impairment including Alzheimer disease or mild cognitive impairment. Specifically, a biomarker for diagnosis of psychiatry disease or cognitive impairment comprising protein fragment or peptide of not less than 5 amino acid residues arising from at least one protein or peptide selected from the group of proteins consisting of amino acid sequence expressed by SEQ ID NOS: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, and 25 and selected from the group of partial peptide in these proteins consisting of amino acid sequence expressed by SEQ ID NOS: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, and 27.

Abstract: Methods are provided that detect cognitive impairment including mild cognitive impairment and Alzheimer disease by using a protein or its partial peptide that differs in presence or absence. Novel biomarkers are also provided for cognitive impairment and non-psychiatric disease, as well as methods for detecting cognitive impairment using such biomarkers. Specifically, a biomarker for diagnosis is provided that comprises a protein fragment or peptide of not less than 5 amino acid residues arising from at least one protein or peptide selected from the group of proteins consisting of an amino acid sequence expressed by SEQ ID NO: 1, 3, 6, 8, 10, 13, 15, 18, or 20 and selected from the group of partial peptide in these proteins consisting of an amino acid sequence expressed by SEQ ID NO: 2, 4, 5, 7, 9, 11, 12, 14, 16, 17, 19, or 21.

Abstract: There are provided a mass spectrum analysis device, a mass spectrum analysis method, and a mass spectrum analysis program capable of accurately analyzing a mass spectrum. The mass spectrum device analyzes a mass spectrum measured for a plurality of samples. The mass spectrum device includes peak position detection means 14 for detecting a peak position where the mass spectrum is at its peak, and coincidence degree calculation means 15 for calculating the coincidence degree of peaks according to the number of peak positions detected in a plurality of mass spectra that is contained in a window having a width for a mass number.