Neurofeedback is a comprehensive training system that promotes change in brain wave patterns and growth at the cellular level of the brain. It is applied to psychotherapy and cognitive-behavioral therapy practices and is becoming increasingly popular due to its non-drug rehabilitation and high rate of success among patients in recovery for substance abuse or mental disorders. Neurofeedback—a specific form of biofeedback that deals with the brain rather than the body—involves the measuring of electric signals (brain waves) by attaching electrodes to the patient’s scalp, and generating an electroencephalogram (EEG) that amplifies and records electrical activity in the brain. The electric signals are classified as different types of brain waves—high-frequency beta waves which deal with concentration, motor skills, and signify a state of alertness/arousal; alpha waves that relate to a resting state of non-arousal; low-frequency theta waves which deal with relaxation and ideation; and delta waves which relate to deep sleep. Patients are taught how to control these electrical patterns in their own brains by responding to cues like images on a screen or sounds from surrounding speakers. Patients learn to manipulate the screen display or frequency of the sound emissions by achieving the mental state that increases production of the desired brain wave. Neurofeedback, also known as neurotherapy, is effective in aiding the treatment of substance abuse disorders, depression, anxiety, posttraumatic stress disorder (PTSD), impulse disorders, obsessive-compulsive disorder (OCD), bipolar disorder, personality disorders, emotional disorders, attention-deficit hyperactivity disorder (ADHD), Asperger’s disorder, seizure disorders, epilepsy, age-related cognitive decline, and closed-head injury victims.