A quantum statistical theory for a laser-driven anharmonic oscillator coupled to a system of many degrees of freedom by means of energy- and phase-dissipative mechanisms is presented. The theory is applied to the description of vibrational dynamics in an admolecule-surface system that are associated with desorption–dissociation processes. It is found that phase relaxation plays an important role in assisting the laser driving force to overcome the anharmonicity and/or detuning bottleneck. It is also shown that a shorter duration of the laser pulse is more efficient for depositing photon energy into the admolecule system.