Attention-deficit/hyperactivity disorder (ADHD or AD/HD) is a neurobehavioral[1] developmental disorder.[2] ADHD is primarily characterized by "the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone."[3] While symptoms may appear to be innocent and merely annoying nuisances to observers, "if left untreated, the persistent and pervasive effects of ADHD symptoms can insidiously and severely interfere with one's ability to get the most out of education, fulfill one's potential in the workplace, establish and maintain interpersonal relationships, and maintain a generally positive sense of self."[4]:p.2

ADHD is the most commonly studied and diagnosed psychiatric disorder in children, affecting about 3 to 5% of children globally with symptoms starting before seven years of age.[5][6] ADHD is a common chronic disorder in children[7] with 30 to 50% of those individuals diagnosed in childhood continuing to have symptoms into adulthood.[8][9] Adolescents and adults with ADHD tend to develop coping mechanisms to compensate for some or all of their impairments.[10] However, many aspects of daily life that most people take for granted are rendered more difficult by the symptoms of ADHD.[
 Pharmacological treatment
Management with medication has been shown to be the most cost-effective, followed by behavioral treatment and combined treatment.[108] Stimulant medication or non-stimulant medication may be prescribed. A 2007 drug class review found that there are no good studies of comparative effectiveness between various drugs for ADHD and that there is a lack of quality evidence on their effects on overall academic performance and social behaviors.[112] The long term effects of ADHD medications in preschool children are unknown and are not recommended for pre-school children.[23][113]

[edit] Stimulant medication
Stimulants are the most commonly prescribed medications for ADHD. The most common stimulant medications are the chain subsitituted amphetamine methylphenidate (Ritalin, Metadate, Concerta), dextroamphetamine (Dexedrine), mixed amphetamine salts (Adderall)[114][115], dextromethamphetamine (Desoxyn)[116] and lisdexamfetamine (Vyvanse).[117]

Stimulants used to treat ADHD raise the extracellular concentrations of the neurotransmitters dopamine and norepinephrine which causes an increase in neurotransmission. The therapeutic benefits are due to noradrenergic effects at the locus coeruleus and the prefrontal cortex and dopaminergic effects at the nucleus accumbens. [118]

One study found that children with ADHD actually need to move more to maintain the required level of alertness while performing tasks that challenge their working memory. Performing math problems mentally and remembering multi-step directions are examples of tasks that require working memory, which involves remembering and manipulating information for a short time. These findings may also explain why stimulant medications improve the behavior of most children with ADHD. Those medications improve the physiological arousal of children with ADHD, increasing their alertness.[35] Previous studies have shown that stimulant medications temporarily improve working memory abilities.

Although "under medical supervision, stimulant medications are considered safe",[95][119] the use of stimulant medications for the treatment of ADHD has generated controversy because of undesirable side effects, uncertain long term effects[11][120][121][122][123] and social and ethical issues regarding their use and dispensation. The FDA has added black-box warnings to some ADHD medications,[124][125] while the American Heart Association and the American Academy of Pediatrics feel that it is prudent to carefully assess children for heart conditions before treating them with stimulant medications.[126]

[edit] Non-stimulant medication
Atomoxetine (Strattera) is currently the only non-stimulant drug approved for the treatment of ADHD. Other medications which may be prescribed off-label include alpha-2A adrenergic receptor blockers such as guanfacine and clonidine, certain antidepressants such as tricyclic antidepressants, SNRIs or MAOIs.[127][128][129][130]

Another non-stimulant drug that has been used to treat ADHD is the analeptic drug modafinil. There have been double-blind randomised controlled trials that have demonstrated the efficacy and tolerability of modafinil[131][132], however there are risks of serious side effects such as skin reactions and modafinil is not recommended for use in children.[133]

[edit] Experimental treatments
Dietary supplements and specialized diets are sometimes used by people with ADHD with the intent to mitigate some or all of the symptoms. For example, Omega-3 supplementation may reduce ADHD symptoms for a subgroup of children and adolescents with ADHD "characterized by inattention and associated neurodevelopmental disorders."[134] Although vitamin or mineral supplements (micronutrients) may help children diagnosed with particular deficiencies, there is no evidence that they are helpful for all children with ADHD. Furthermore, megadoses of vitamins, which can be toxic, must be avoided.[135] In the United States, no dietary supplement has been approved for the treatment for ADHD by the FDA.[136]

EEG biofeedback is a treatment strategy used for children, adolescents and adults with ADHD.[137] The human brain emits electrical energy which is measured with electrodes on the brain. Biofeedback alerts the patient when beta waves are present. This theory believes that those with ADHD can train themselves to decrease ADHD symptoms. There is a distinct split in the scientific about the effectiveness of the treatment. A number of studies indicates that the scientific evidence has been increasing in recent years for the effectiveness of EEG biofeedback for the treatment of ADHD. According to a 2007 review, with effectiveness of the treatment was demonstrated to be equivalent to that of stimulant medication. The review noted, improvements are seen at the behavioral and neuropsychological level with the symptoms of inattention, hyperactivity and impulsivity showing significant decreases after treatment. There are no known side effects from EEG biofeedback therapy. There are methodological limitations and weaknesses in study designs however. In a 2005 review, Loo and Barkley stated that problems including lack of blinding such as placebo control and randomisation are significant limitations to the studies into EEG biofeedback and make definitive conclusions impossible to make.[138] As a result more robust clinical studies have been strongly recommended.[139] A German review in 2004 found that EEG biofeedback, also sometimes referred to as neurofeedback, is more effective than previously thought in treating attention deficiency, impulsivity and hyperactivity; short-term effects match those of stimulant treatment and a persistent normalization of EEG parameters is found which is not found after treatment with stimulants.[140] There are no known side effects from biofeedback therapy although research into biofeedback has been limited and further research has been recommended.[140] An American review the following year also emphasized the benefits of this method.[141] Similar findings were reported in a study by another German team in 2004.[142]

Aerobic fitness may improve cognitive functioning and neural organization related to executive control during pre-adolescent development, though more studies are needed in this area.[143] One study suggests that athletic performance in boys with ADHD may increase peer acceptance when accompanied by fewer negative behaviors.[144]