Tetraisoquinololine derivatives as modulators of dopamine d3 receptors

Compounds of formula (I), wherein: R1 represents a substituent selected from: a hydrogen or halogen atom; a hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, trifluoromethanesulfonyloxy, pentafluoroethyl, C1-4alkyl, C1-4alkoxy, arylC1-4alkoxy, C1-4alkylthio, C1-4alkoxyC1-4alkyl, C3-6cycloalkylC1-4alkoxy, C1-4alkanoyl, C1-4alkoxycarbonyl, C1-4alkylsulfonyl, C1-4alkylsulfonyloxy, C1-4alkylsulfonylC1-4alkyl, arylsulfonyl, arylsulfonyloxy, arylsulfonylC1-4alkyl, C1-4alkylsulfonamido, C1-4alkylamido, C1-4alkylsulfonamidoC1-4alkyl, C1-4alkylamidoC1-4alkyl, arylsulfonamido, arylcarboxamido, arylsulfonamidoC1-4alkyl, arylcarboxamidoC1-4alkyl, aroyl, aroylC1-4alkyl, or arylC1-4alkanoyl group; a group R3OCO(CH2)p, R3CON(R4)(CH2)p, R3R4NCO(CH2)p or R3R4NSO2(CH2)p where each of R3 and R4 independently represents a hydrogen atom or a C1-4alkyl group or R3R4 forms part of a C3-6azacyloalkane or C3-6(2-oxo)azacycloalkane ring and p represents zero or an integer from 1 to 4; or a group Ar1-Z, wherein Ar1 represents an optionally substituted phenyl ring or an optionally substituted 5- or 6-membered aromatic heterocyclic ring and Z represents a bond, O, S, or CH2; R2 represents a hydrogen atom or a C1-4alkyl group; q is 1 or 2; A represents a group of formula -(CH2)r-V-CH2)s-Ar wherein r and s independently represent an integer from zero to 3 such that the sum of r and s is