1. A method comprising: determining, by a processor, an efficacy threshold value of at least one electrical stimulation parameter based on a first volume of tissue activation expected to result from delivery of electrical stimulation by at least one electrode to a patient; and determining, by the processor, an adverse-effects threshold value of the at least one stimulation parameter based on a second volume of tissue activation expected to result from delivery of electrical stimulation by the at least one electrode to the patient.