This invention relates to N-aroyl cyclic amine derivatives and their use as orexin antagonists ##STR00001## wherein: Y represents a bond, oxygen, or a group (CH.sub.2).sub.n, wherein n represents 1, 2 or 3; m represents 1, 2, or 3; p represents ) or 1; X is NR, wherein R is H or (C.sub.1-4)alkyl; Ar.sup.1 is aryl, or a mono or bicyclic heteroaryl group containing up to 3 heteroatoms selected from N, O and S; any of which may be optionally substituted; A.sup.2 represents phenyl or a 5- or 6-membered heterocyclyl group containing up to 3 heteroatoms selected from N, O and S, wherein the phenyl or heterocyclyl group is substituted by R.sup.1 and further optional substituents; or Ar.sup.2 represents an optionally substituted bicyclic aromatic or bicyclic heteroaromatic group containing up to 3 heteroatoms selected from N, O and S; R.sup.1 represents hydrogen, optionally substituted (C.sub.1-4)alkoxy, halo, cyano, optionally substituted (C.sub.1-6)alkyl, optionally substituted phenyl, or an optionally substituted 5- or 6-membered heterocyclyl group containing up to 4 heteroatoms selected from N, O and S; when Ar.sup.1 is aryl p is not 1, or a pharmaceutical acceptable salt thereof.