ADHD | Graphics Demo

Summary

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, bouts of excessive energy, hyper-fixation, and impulsivity, which are otherwise not appropriate for a person's age.[1][2][3][4] Some individuals with ADHD also display difficulty regulating emotions or problems with executive function.[1][5][6][7] For a diagnosis, the symptoms have to be present for more than six months, and cause problems in at least two settings (such as school, home, work, or recreational activities).[1][2] In children, problems paying attention may result in poor school performance.[8] Additionally, it is associated with other mental disorders and substance use disorders.[9] Although it causes impairment, particularly in modern society, many people with ADHD can have sustained attention for tasks they find interesting or rewarding (known as hyperfocus)

History

The medical literature has described symptoms similar to those of ADHD since the 18th century.[40] ADHD, its diagnosis, and its treatment have been considered controversial since the 1970s.[41] The controversies have involved clinicians, teachers, policymakers, parents, and the media. Topics include ADHD's causes and the use of stimulant medications in its treatment.[42] Most healthcare providers accept ADHD as a genuine diagnosis in children and adults, and the debate in the scientific community mainly centers on how it is diagnosed and treated.[43][44] The condition was officially known as attention deficit disorder (ADD) from 1980 to 1987, while before this it was known as hyperkinetic reaction of childhood.[45][46]

Symptoms

Inattention, hyperactivity (restlessness in adults), disruptive behavior, and impulsivity are common in ADHD.[47][48] Academic difficulties are frequent as are problems with relationships.[47] The symptoms can be difficult to define, as it is hard to draw a line at where normal levels of inattention, hyperactivity, and impulsivity end and significant levels requiring interventions begin.[49] According to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), symptoms must be present for six months or more to a degree that is much greater than others of the same age.[1] they must cause significant problems functioning in at least two settings (e.g., social, school/work, or home).[1] The criteria must have been met before age twelve to receive a diagnosis of ADHD.[1] This requires at least 6 symptoms of inattention or hyperactivity/impulsivity for those under 17 and at least 5 for those 17 years or older.[1]

Pathophysiology

Current models of ADHD suggest that it is associated with functional impairments in some of the brain's neurotransmitter systems, particularly those involving dopamine and norepinephrine.[131][132] The dopamine and norepinephrine pathways that originate in the ventral tegmental area and locus coeruleus project to diverse regions of the brain and govern a variety of cognitive processes.[131][133] The dopamine pathways and norepinephrine pathways which project to the prefrontal cortex and striatum are directly responsible for modulating executive function (cognitive control of behavior), motivation, reward perception, and motor function;[131][132][133] these pathways are known to play a central role in the pathophysiology of ADHD.[131][133][134][135] Larger models of ADHD with additional pathways have been proposed.[132][134][135]

Causes

Despite being the most commonly studied and diagnosed mental disorder in children and adolescents, the precise cause or causes are unknown in the majority of cases.[12] Genetic factors are estimated to make up about 75% of the risk.[13] Nicotine exposure during pregnancy may be an environmental risk.[14] It does not appear to be related to the style of parenting or discipline.[15] It affects about 5–7% of children when diagnosed via the DSM-IV criteria[1][16] and 1–2% when diagnosed via the ICD-10 criteria.[17] As of 2019, it was estimated to affect 84.7 million people globally.[18] Rates are similar between countries and differences in rates depend mostly on how it is diagnosed.[19] ADHD is diagnosed approximately two times more often in boys than in girls,[1] although the disorder is often overlooked in girls because their symptoms are often less disruptive.[20][21][22] About 30–50% of people diagnosed in childhood continue to have symptoms into adulthood and between 2–5% of adults have the condition.[23][24][25] In adults, inner restlessness, rather than hyperactivity, may occur.[26] Adults often develop coping skills which compensate for some or all of their impairments.[27] The condition can be difficult to tell apart from other conditions, as well as from high levels of activity within the range of normal behavior.[28]

Treatment

The management of ADHD typically involves counseling or medications either alone or in combination. While treatment may improve long-term outcomes, it does not get rid of negative outcomes entirely.[166] Medications used include stimulants, atomoxetine, alpha-2 adrenergic receptor agonists, and sometimes antidepressants.[64][140] In those who have trouble focusing on long-term rewards, a large amount of positive reinforcement improves task performance.[147] ADHD stimulants also improve persistence and task performance in children with ADHD.[132][147]