The ideal magnetohydrodynamic Mercier criterion for the stability of localized interchange modes is easily violated by modest pressure gradients in the central region of a tokamak plasma where the magnetic winding index q drops below unity. However, kinetic effects can substantially modify this criterion, allowing for stable peaked pressure profiles. In this paper, we discuss the modifications to the Mercier criterion brought about by high-energy particles and by the thermal trapped ions in the collisionless Kruskal-Oberman regime.