The present invention provides a diagnostic agent for eatingdisorders comprising as an active ingredient an antibody against brain-derivedneurotrophic factor, and a method for detecting eating disorderscomprising measuring of the concentration of a brain-derived neurotrophicfactor in blood. Particularly, the eating disorders can easily be diagnosedby measuring the concentration of a brain-derived neurotrophic factor inblood of the patients with an antibody against brain-derived neurotrophicfactor and a labeled antibody against brain-derived neurotrophic factor.
