A compound of formula (I): in which A represents optionally substituted monocyclic heteroaryl or phenyl B represents optionally substituted heteroaryl, aryl, aryl-fused-heterocycloalkyl, heteroaryl-fused-cycloalkyl, heteroaryl-fused-heterocycloalkyl or aryl-fused-cycloalkyl X and Y, which may be the same or different, each independently represent -0-, -NR1-, CO-, -S02-, -SO-, -S-, -NR1CO-, -NR1S02-, -CONR1-, -SO2NR1-, -NR1CONR1 or X may be a direct bond when Y represents -NR1-, -NR1CO-, -NR1SO2-, -CONR1-, - SO2NR1- or -NR1CONRI- provided that R1 represents alkyl substituted by -OR2,-NR3R4, - NR4COR5, -NR4SO2R5, -CONR3R4 or -S02NR3R4 R1 represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, or alkyl substituted by -OR2, -NR3R4, -NR4COR5, -NR4S02R5, -CONR3R4 or -S02NR3R4 R2 represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, heteroaryl, heterocycloalkyl or cycloalkyl R3 represents H or alkyl R4 represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, heteroaryl, heterocycloalkyl or cycloalkyl or NR3R4 represents a cyclic amine R5 represents alkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, heterocycloalkylalkyl n represents 0-3 m represents 1-3 p represents 0-3 and corresponding N-oxides, pharmaceutically acceptable salts, solvates and prodrugs thereof; and use to treat a disease in which inhibition of histone deacetylase can prevent, inhibit or ameliorate the pathology and/or symptomatology of the disease.