A system comprising: a medical device comprising: a memory; and processing circuitry configured to: a) determine a present power value of power in a frequency band in a bioelectric signal, generated in a brain, in response to delivery of present electrical stimulation having a present therapy parameter value; b) determine a power band difference value between the present power value and a previous power value, wherein the previous power value is indicative of power in the frequency band in a previous bioelectric signal, generated in the brain, in response to delivery of a previous electrical stimulation having a previous therapy parameter value different than the present therapy parameter value, and wherein the power value is stored in the memory; compare the power band difference value to a threshold value; based on the power band difference value being greater than or equal to the threshold value, iteratively set the previous therapy parameter value for a next iteration step equal to the present therapy parameter value and adjust the present therapy parameter value for the next iteration step until the power band difference value determined according to steps a) and b) is less than the threshold value; set a final therapy parameter value based on the present therapy parameter value; and cause delivery of electrical stimulation having the final therapy parameter value. a memory; and processing circuitry configured to: a) determine a present power value of power in a frequency band in a bioelectric signal, generated in a brain, in response to delivery of present electrical stimulation having a present therapy parameter value; b) determine a power band difference value between the present power value and a previous power value, wherein the previous power value is indicative of power in the frequency band in a previous bioelectric signal, generated in the brain, in response to delivery of a previous electrical stimulation having a previous therapy parameter value different than the present therapy parameter value, and wherein the power value is stored in the memory; a) determine a present power value of power in a frequency band in a bioelectric signal, generated in a brain, in response to delivery of present electrical stimulation having a present therapy parameter value; b) determine a power band difference value between the present power value and a previous power value, wherein the previous power value is indicative of power in the frequency band in a previous bioelectric signal, generated in the brain, in response to delivery of a previous electrical stimulation having a previous therapy parameter value different than the present therapy parameter value, and wherein the power value is stored in the memory; compare the power band difference value to a threshold value; based on the power band difference value being greater than or equal to the threshold value, iteratively set the previous therapy parameter value for a next iteration step equal to the present therapy parameter value and adjust the present therapy parameter value for the next iteration step until the power band difference value determined according to steps a) and b) is less than the threshold value; set a final therapy parameter value based on the present therapy parameter value; and cause delivery of electrical stimulation having the final therapy parameter value.