Research consistently indicates that clients maintain their improvements from neurofeedback training. Several research studies looking at the effects of neurofeedback at the end of treatment and a year later, have demonstrated that additional gains are made over that year as the individual continues to practice what they learned during neurofeedback treatment.
Dr. Joel Lubar from the University of Tennessee has carried out longitudinal studies on the long term effects of neurofeedback training. He reports that ADD clients sustain their improvements gained from the neurofeedback training for up to 20 years.
Obviously head injuries or other brain trauma post treatment could cause new issues that will require treatment.