1. A method for treating a neurological condition of a patient, comprising: applying electromagnetic signals to a patient's nervous system over a first time period with a first waveform having a first set of parameters; and applying electromagnetic signals to the patient's nervous system over a second time period with a second waveform having a second set of parameters, wherein at least one parameter of the second set is different than a corresponding parameter of the first set, and wherein the at least one parameter is selected to resume, at least approximately maintain, or resume and at least approximately maintain a therapeutic benefit resulting from signals applied during the first time period.