Provided is a marker for determining a mental disease, which can be used in an objective diagnosis of such a mental disease. A marker for determining a mental disease, containing one or more enterobacteria selected from the group consisting of Bifidobacterium, Lactobacillus, Lactobacillus brevis, Lactobacillus reuteri subgroup, Lactobacillus sakei subgroup, Atopobium cluster, Bacteroides fragilis group, Enterococcus, Clostridium coccoides group, Clostridium leptum subgroup, Staphylococcus, Clostridium perfringens and Enterobacteriaceae.
BIOMARKER FOR MENTAL DISEASE