PROBLEM TO BE SOLVED: To provide a method for screening an unerring therapeutic agent for dementia at an individual level.SOLUTION: A transgenic non-human animal in which a dementia-related gene is expressed is created by introducing an expression vector carrying the dementia-related gene into the inner ear hair cells of a non-human animal being a test subject. A candidate compound is administered to a transgenic non-human animal in which the dementia-related gene is expressed. Sense of hearing of the transgenic non-human animal in which the candidate compound is administered is detected. In such a case where the degree of hearing disorder in a transgenic non-human animal in which a candidate compound is administered is more dissolved than the degree of hearing disorder in a transgenic non-human animal in which a candidate compound is not administered, the candidate compound is determined to be effective as a therapeutic agent for dementia.
