The present invention relates to heterocyclic derivatives of formula (I) wherein R represents halogen, C.sub.1-4 alkyl, cyano, C.sub.1-4 alkoxy, trifluoromethyl or trifluoromethoxy; R.sub.1 represents a 5 or 6 membered heteroaryl group, in which the 5-membered heteroaryl group contains at least one heteroatom selected from oxygen, sulphur or nitrogen and the 6-membered heteroaryl group contains from 1 to 3 nitrogen atoms, or R.sub.1 represents a 4, 5 or 6 membered heterocyclic group, wherein saids 5 or 6 membered heteroaryl or the 4, 5 or 6 membered heterocyclic group may optionally be substituted by one to three substituents, which may be the same or different, selected from (CH.sub.2).sub.pR.sub.6, wherein p is zero or an integer from 1 to 4 and R.sub.6 is selected from: halogen, C.sub.1-4alkoxy, C.sub.1-4alkyl, C.sub.3-7cycloalkyl, C.sub.1-4 alkyl optionally substituted by halogen, cyano or C.sub.1-4 alkoxy, hydroxy, cyano, nitro, trifluoromethyl, carboxy, NH(C.sub.1-4 alkyl), N(C.sub.1-4 alkyl).sub.2 NH(C.sub.3-7 cycloalkyl), N(C.sub.1-4 alkyl)(C.sub.3-7 cycloalkyl); NH(C.sub.1-4alkylOC.sub.1-4alkoxy), OC(O)NR.sub.7R.sub.8, NR.sub.8C(O)R.sub.7 or C(O)NR.sub.7R.sub.8; R.sub.2 represents hydrogen, or C.sub.1-4 alkyl; R.sub.3 and R.sub.4 independently represent hydrogen, C.sub.1-4 alkyl or R.sub.3 together with R.sub.4 represents C.sub.3-7 cycloalkyl; R.sub.5 represents trifluoromethyl, S(O).sub.qC.sub.1-4 alkyl, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, trifluoromethoxy, halogen or cyano; R.sub.7 and R.sub.8 independently represent hydrogen, C.sub.1-4 alkyl or C.sub.3-7 cycloalkyl; L is a single or a double bond; n is an integer from 1 to 3; m is zero or an integer from 1 to 3; q is zero or an integer from 1 to 2; provided that a) when L is a double bond, R.sub.1 is not an optionally substituted 5 or 6 membered heteroaryl group, in which the 5-membered heteroaryl group contains at least one heteroatom selected from oxygen, sulphur or nitrogen and the 6-membered heteroaryl group contains from 1 to 3 nitrogen atoms; b) the group R.sub.1 is linked to the carbon atom shown as * via a carbon atom; and c) when the heteroatom contained in the group R.sub.1 is substituted, p is not zero; and pharmaceutically acceptable salts and solvates thereof; process for their preparation and their use in the treatment of conditions mediated by tachykinins and/or by selective inhibition of serotonin reuptake transporter protein.