Do you need adhesive for thermostat gaskets?

On some of the older models (4-5 years or more) most mechanics use a light coat of gasket sealer to hold the gasket in place until the gasket housing is torqued down. Some thermostat gaskets come with a gasket already coated with a peel off to help hold it in place. On most newer models they use a rubber "O" ring or seal and no gasket is required.