The invention provides compounds of formula (I): wherein A and B represent the groups —(CH2)m— and —(CH2)n— respectively; R1 represents hydrogen or C1-6alkyl; R2 represents hydrogen, halogen, hydroxy, cyano, nitro, hydroxyC1-6alkyl, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, C1-6fluoroalkoxy, —(CH2)pC3-6cycloalkyl, —(CH2)pOC3-6cycloalkyl, —COC-6alkyl, —SO2C1-6alkyl, —SOC1-6alkyl, —S—C1-6alkyl, —CO2C1-6alkyl, —CO2NR5R6, —SO2NR5R6, —(CH2)NR5R6, —(CH2)pNR5COR6, optionally substituted aryl ring, optionally substituted heteroaryl ring or optionally substituted heterocyclyl ring; R3 represents hydrogen, halogen, hydroxy, cyano, nitro, hydroxyC1-6alkyl, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, C1-6fluoroalkoxy, —(CH2)pC3-6cycloalkyl, —(CH2)pOC3-6cycloalkyl, —COC1-6alkyl, —SO2C1-6alkyl, —SOC1-6alkyl, —S—C1-6alkyl, —CO2C1-6alkyl, —CO2NR7R8, —SO2NR7R8, —(CH2)pNR7R8 or —(CH2)pNR7COR8; R4represents hydrogen, hydroxy, C1-6alkyl, C1-6alkoxy, C1-6fluoroalkoxy, trifluoromethyl, trifluoromethoxy, halogen, —OSO2CF3, —(CH2)pC3-6cycloalkyl, —(CH2)qOC1-6alkyl or —(CH2)pOC3-6cycloalkyl; R5 and R6 each independently represent hydrogen, C1-6alkyl or, together with the nitrogen or other atoms to which they are attached, form an azacycloalkyl ring or an oxo-substituted azacycloalkyl ring; R7 and R8 each independently represent hydrogen or C1-6alkyl; m and n independently represent an integer selected from 1 and 2; p independently represents an integer selected from 0, 1, 2 and 3; q independently represents an integer selected from 1, 2 and 3; or a pharmaceutically acceptable salt or solvate thereof, with the proviso that the compounds 8-hydroxy-3-methyl-7-phenylsulfonyl-2,3,4,5-tetrahydro-1H-3-benzazepine, 8-hydroxy-7-4-(hydroxyphenyl)sulfonyl-2,3,4,5-tetrahydro-1H-3-benzazepine, 7-phenylsulfonyl- 1,2,3,4-tetrahydroisoquinoline and 7-phenylsulfonyl-1,2,3,4-tetrahydroisoquinoline hydrochloride are excluded. The compounds are useful in therapy, in particular as antipsychotic agents