Methods and apparatus provide automated controls for a respiratory pressure therapy device, such as a servo-ventilator. For example, a controller of a respiratory pressure therapy device may control application of pressure support ventilation therapy to an airway of a patient. The controller may control the respiratory pressure therapy device to auto-titrate an expiratory positive airway pressure (EPAP) of a pressure support ventilation therapy so as to maintain airway patency of the patient. The EPAP may be bounded below by a floor pressure limit. The controller may control the respiratory pressure therapy device to repeatedly adjust the floor pressure limit depending on events of interest during the auto-titration of the EPAP. Such methodologies may improve treatment for patients such as those suffering from sleep disordered breathing-comorbid hyperarousal disorders.