A relativistic quantum mechanics is studied for bound hadronic systems in the
framework of the Point Form Relativistic Hamiltonian Dynamics. Negative energy
states are introduced taking into account the restrictions imposed by a correct
definition of the Poincar\'e group generators. We obtain nonpathological,
manifestly covariant wave equations that dynamically contain the contributions
of the negative energy states. Auxiliary negative energy states are also
introduced, specially for studying the interactions of the hadronic systems
with external probes.Comment: 42 pages, submitted to EPJ