The invention relates to the treatment or control of unipolar depressive disorder by administering a compound of Formula I or a salt thereofto a subject； Formula I wherein: E is S or Se； R1 and R2 are optional substituents, and are at each occurrence independently selected from: (1) a halogen, which is preferably selected from F, CI and Br； (2) C1-C4 alkyl, such as C1-C2 alkyl or Ci alkyl, optionally substituted with one or more halogen atoms, each of which is preferably selected from F, CI and Br； and (3) C1-C4 alkoxy, such as C1-C2 alkoxy or C1 alkoxy； optionally substituted with one or more halogen atoms, each of which is preferably selected from F, CI and Br； m is an integer in the range of from 0 to 5； and n is an integer in the range of from 0 to 4.
