1. A deep brain stimulator device comprising: an implantable chemosensor selected from the group consisting of a dopamine-sensitive chemosensor and a glutamate sensitive chemosensor; an implantable stimulus electrode for electrical stimulation to a brain; a programmable feedback controller coupled to the chemosensor and the implantable stimulus electrode; wherein the feedback controller reads the chemosensor and provides a sequence of high frequency electrical stimulation (HFS) pulses through the stimulus electrode such that a greater number of HFS pulses are provided when levels of a neurochemical measured with the chemosensor are less than a programmed level than a number of HFS pulses provided when levels of the neurochemical measured with the chemosensor are greater than the programmed level; wherein the chemosensor and the stimulus electrode are adapted for implantation in separate neurological structures of the brain; wherein the HFS comprises electrical pulses at a rate of between one hundred and one hundred eighty pulses per second and of width between ten and twenty-five microseconds; and wherein the HFS pulses have a selected pulse parameter selected from the group consisting of voltage or current, and wherein an amplitude of the selected pulse parameter is inversely proportional to the neurochemical level as measured by the chemosensor.