Compounds for use in the treatment or prophylaxis of an affective disorder, which compound is represented by formula I: in which: the dotted line represents a single or a double bond； and R5 and R5&prime； are independently &mdash；H, &mdash；OH or &mdash；OR6, where R6 is a linear or branched C1-C4 alkyl； X is &mdash；CH2O&mdash；； Z is &mdash；CH2CH2O&mdash；, &mdash；CH(CH3)CH2O&mdash； or &mdash；CH2CH(CH3)O&mdash；； m is 1； and n is an integer of 1-5； or a pharmaceutically acceptable salt, prodrug, metabolite, or hydrate thereof.
