Abstract: This invention provides pharmaceutically active enantiomers of the venlafaxine metabolite O-Desmethyl venlafaxine, R(−)-4-[2-(Dimethylamino-1-(1-hydroxycyclo-hexyl)ethyl]phenol or R(−)1-[2-(dimethylamino)-1-(4-hydroxyphenyl)ethyl]cyclo-hexanol, and S(+)-1-[2-(Dimethylamino)-1-(4-hydroxyphenyl)ethyl]cyclohexanol or S(+)-4-[2-(Dimethylamino)-1-(1-hydroxycyclohexyl)ethyl]phenol, or one or more pharmaceutically acceptable salts or salt hydrates thereof, as well as pharmaceutical compositions utilizing these enantiomers and methods of using the enantiomers to treat, inhibit or control central nervous system disorders.