The present invention relates to a medicine for preventing and/or treating stress-induced diseases, said medicine being characterized in that (1S)-2-acetyl-1-(4-chloro-2-methoxyphenyl)-5-fluoro-1,2,3,9-tetrahydrospiro[β-carboline-4,1'-cyclopropane] is administered at such a specific dose that a brain TSPO occupancy required for the development of the pharmacological activity of the medicine can be obtained.
