An automatic positive airway pressure (AutoPAP) therapy device can be configured such that the minimum and/or maximum pressures deliverable by the device can automatically change. The minimum and/or maximum pressures can change as a function of pressures delivered over the course of the current therapy session and/or over the course of prior therapy sessions. The minimum and/or maximum pressures can also change as a function of the presence, absence, type, severity, or length of sleep disordered breathing events (SDBE) detected by the device over the course of the current therapy session and/or over the course of prior therapy sessions.