Neurofeedback (NFB), also called neurotherapy or neurobiofeedback, is a type of biofeedback that uses real-time displays of brain activity—most commonly electroencephalography (EEG), to teach self-regulation of brain function. Typically, sensors are placed on the scalp to measure activity, with measurements displayed using video displays or sound.

Uses

ADHD

Clinical guidelines on neurofeedback as a treatment for ADHD are mixed. Biofeedback is graded by the American Academy of Pediatrics with their Level 2 evidenced based treatment for ADHD. [unreliable source?] The NICE guideline for ADHD leaves the efficacy of biofeedback an open question (p. 412). In page 202 states "Biofeedback has been employed as a non-invasive treatment for children with ADHD since the 1970s but is probably not used as a significant intervention in UK clinical practice". However this is unsurprising since in the UK, NICE evaluates whether treatments should be recommended on the basis of the cost of a quality-adjusted life year. SIGN guideline no 112 in page 24 mentions "Neurofeedback is presently considered to be an experimental intervention in children and young people with ADHD/HKD. There are no standardised interventions". Institute for Clinical Systems Improvement guideline on Diagnosis and Management of Attention Deficit Hyperactivity Disorder in Primary Care for School-Age Children and Adolescents in page 41 mentions neurofeedback lacks enough research evidence for efficacy in ADHD.

Overall research into neurofeedback is considered to have been limited and of low quality, although others have disagreed
It has been argued there is some indication on the effectiveness of biofeedback for ADHD but that it is not conclusive: several studies have yielded positive results, however the best designed ones have either shown absent or reduced effects. Other experts have proposed that standard neurofeedback protocols for ADHD, such as theta/beta, SMR and slow cortical potentials neurofeedback are well investigated and have demonstrated specificity. No serious adverse side effects from neurofeedback have been reported.

QEEG has been used to develop EEG models of ADHD. According to this model, persons with ADHD often have too many slow theta brain waves (associated with relaxation) and not enough fast beta wave activity (associated with mental focus). Neurofeedback therapies for ADHD generally attempt to increase the production of betawaves and decrease the number of slower brain waves. This can be accomplished by allowing the patient to view their levels of brain waves on a screen and attempt to alter them, or by integrating brain waves into a video game.

Other medical uses

Research shows neurofeedback may be a potentially useful intervention for a range of brain-related conditions. It has been used for pain, anxiety, autism depression, Schizophrenia, epilepsy, headaches, insomnia, Tourette syndrome, and brain damage from stroke, trauma, and other causes.
It is also used to treat other less well known disorders, such as Auditory Processing Disorder and working memory deficit.

Non-medical

The applications of neurofeedback to enhance performance extend to the arts in fields such as music, dance, and acting. A study with conservatoire musicians found that alpha-theta training benefitted the three music domains of musicality, communication, and technique. Historically, alpha-theta training, a form of neurofeedback, was created to assist creativity by inducing hypnagogia, a “borderline waking state associated with creative insights”, through facilitation of neural connectivity. Alpha-theta training has also been shown to improve novice singing in children. Alpha-theta neurofeedback, in conjunction with heart rate variability training, a form of biofeedback, has also produced benefits in dance by enhancing performance in competitive ballroom dancing and increasing cognitive creativity in contemporary dancers. Additionally, neurofeedback has also been shown to instil a superior flow state in actors, possibly due to greater immersion while performing.

Source: https://en.wikipedia.org/wiki/Neurofeedback