The invention relates to novel amidoalkylpiperazinyl derivatives of tricyclic heterocyclic systems of general formula (I), wherein Z represents -NH- and X represents -S-, or Z represents -S- and X represents >C=C1 represents H or -CH3, R6 and R7 both represent H, n is an integer from 0 to 4 inclusive, G represents a cyclic amide or imide moiety, and optical isomers, geometric isomers, and pharmaceutically acceptable salts thereof. The compounds may be useful for the treatment and/or prevention of the central nervous system disorders.
