Attention-deficit/hyperactivity disorder (ADHD) is a developmental mental disorder characterized by persistent symptoms of inattention or inattention in combination with hyperactivity and impulsivity. Its prevalence may be up to one in four [1, 2]. The severity of these symptoms and its enduring nature are known to impair a person’s capacity to effectively function. Treatment programs using behavioral and pharmacotherapeutic approaches are well established [3, 4]. The Multimodal Treatment study (MTA) of ADHD identified advantages of multimodal treatment [1, 5, 6]. Because of rapid improvements in attention and reduced hyperactivity, many children with ADHD have been treated with stimulants [7–9]. However, improvements in social and academic skills following stimulant treatment have not been reported . In addition, concerns with the benefits and side effects of long-term stimulant treatment have also been noted [10, 11].
Many clinical trials have found that neurofeedback (NF) effectively treats the symptoms of ADHD [12, 13]. The effects of NF have been described as improved attention, decreased hyperactivity, and increased academic and social skills [1, 14, 15]. However, other studies have only found improvements in attention , and two studies with large sample sizes did not find significant improvements in core ADHD symptoms [11, 17].
NF has been discussed as being an effective ADHD treatment when given alone or in combination with medications . One study did not find significant treatment responses between Ritalin and NF .
NF is a learning process in which the brain is rewarded for positive changes in its activity . The response to this learning process is visual or auditory feedback. In NF, the placement of the electrodes and the frequency of stimulation are important. The International 10-20 system is a recognized method to describe and apply the location of scalp electrodes in the context of an electroencephalography (EEG) exam or experiment. Most NF studies have used the standardized electrode placements Cz, C3, and C4 . Some studies included frontal electrodes when using NF to treat ADHD, such as the Fz, F3, and F4 electrodes . Several NF protocols for treating ADHD are available. Single-channel protocols (unipolar) developed by Lubar and interhemispheric (bipolar) protocols developed by Othmers are widely practiced and supported by large-scale clinical studies [18–20].
Different approaches regarding NF treatment have been developed for ADHD [1, 12, 21]. The most frequently used frequencies enhance beta (15-18 Hz) and inhibit theta (4-7 Hz) brain activity . Sensorimotor rhythm (SMR; 12-15 Hz) protocols that enhance SMR activity (low beta activity), alpha/theta (8–11 Hz/4–7 Hz) protocols that enhance alpha brain activity, and SCP (slow cortical potentials) protocols that reward polarity changes in EEGs are also used . Usually no more than two different treatment protocols are used in NF treatments .
The lack of large and controlled studies may have limited the use of NF treatments in the clinic [24–27]. Many prospective controlled studies have used either stimulants or waiting lists as the control groups . Only a few studies were randomized and controlled trials [16, 17, 28–30].
In addition, several non-randomized studies found a large effect size (ES) for attention and a medium ES for hyperactivity , but a randomized study by Arns and Linden found a small ES for hyperactivity [14, 32].
Use of sham feedback (placebo) for evaluating the efficacy of NF in the ADHD population was declared unethical by the University of California, San Diego [24, 33]. This is the most likely reason why standard medication treatments have been applied to the control groups in NF research studies.
The present study was a controlled and randomized clinical study that included children and adolescents with ADHD, who were followed at a Child and Adolescent Mental Health Clinic in Norway. The aim of the study was to evaluate the effects of NF on the core symptoms of ADHD, including attention and hyperactivity.