Attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders of childhood. It is usually diagnosed in childhood and lasts into adulthood. ADHD affects how a person is able to pay attention, sit still, and control their behavior.

Those with ADHD often experience an ongoing pattern of symptoms such as inattention, hyperactivity, and impulsivity. With ADHD-related inattention, a person has difficulty staying on task, sustaining focus, staying organized, and having other related problems that are determined not to be due to defiance or lack of comprehension. Hyperactivity symptoms include moving constantly, including in situations when it is not appropriate. And impulsivity occurs when a person acts without thinking or having difficulty with self-control.

ADHD has also been known as attention deficit disorder (ADD) before it was known as attention deficit hyperactivity disorder. For a period of time, ADD and ADHD were commonly considered to be different, if related, conditions. The condition was officially changed in the 1990s, with ADHD being the proper name for the disorder, although it is still referred to at times as ADD.

ADHD is most commonly diagnosed in children between the ages of six to twelve years old, when symptoms appear. Often these symptoms of ADHD improve with age, but those diagnosed at a young age often continue to experience problems related to the condition through their life. Furthermore, males are more likely to be diagnosed or have ADHD than females, and it is usually spotted in early school years when a child begins to have problems paying attention.

According to some sources, an estimated 8.4 percent of children and 2.5 percent of adults have ADHD. Other sources estimate that about 4 percent to 12 percent of children have ADHD, with boys often being two to three times as likely to have ADHD than girls.

Dependent on the types of symptoms, ADHD is often classified into three types of presentations. These include the combined presentation, the predominantly inattentive presentation, and the predominantly hyperactive-impulsive presentation.

Symptoms of ADHD tend to be noticed at an early age and may become more noticeable when a child's circumstances change, such as when they start school. While many children will go through phases of restlessness or inattentiveness, this is considered normal and does not necessarily mean these children have ADHD. However, when a child's teacher, general practitioner, or a school's special educational coordinator think a child's behavior may be abnormal for their age, it is considered a good idea to get the child tested.

In determining if a child has ADHD, there is a requirement to determine if the symptoms are atypical of a normal child's behavior. The difference in children with ADHD is that their hyperactivity and inattention are noticeably greater than expected for their age and often cause distress or problems functioning at home, at school, or with friends. The symptoms are often split between inattentiveness and hyperactivity of impulsivity.

For inattentiveness, symptoms that occur frequently include the following:

• When a person does not pay close attention to details and makes careless mistakes in school or job tasks
• When a person has problems staying focused on tasks or activities, such as during lectures, conversations, or long reading
• When a person does not seem to listen when spoken to
• When a person does not follow through on instructions and does not complete schoolwork, chores, or job duties
• When a person has problems organizing tasks and work
• When a person avoids or dislikes tasks that require sustained mental effort, such as preparing reports and completing forms
• When a person often loses things needed for tasks or daily life, such as school papers, books, keys, wallet, cell phone, and eyeglasses
• When a person is easily distracted
• When a person forgets daily tasks, such as doing chores and running errands

For hyperactivity and impulsivity, frequently occurring symptoms include the following:

• When a person fidgets with or taps hands or feet, or squirms in their seat
• When a person is not able to stay seated
• When a person runs about or climbs where it is inappropriate
• When a person is unable to play or do leisure activities quietly
• When a person is always "on the go" as if driven by a motor
• When a person talks too much
• When a person blurts out an answer before a question has been finished
• When a person has difficulty waiting his or her turn, such as while waiting in line
• When a person interrupts or intrudes on others. Older teens and adults make take over what others are doing

Although it is not always the case, those who have ADHD often have signs of other cognitive or neural problems or conditions alongside ADHD, including the following:

• Anxiety disorder, which can cause a person to worry and be nervous much of the time; may also cause physical symptoms such as a rapid heartbeat, sweating, and dizziness
• Oppositional defiant disorder, which often involves highly antisocial behavior, such as stealing, fighting, vandalism, and harming people or animals
• Depression
• Sleep problems, such as difficulty getting to sleep or having irregular sleep patterns
• Autistic spectrum disorder (ASD)
• Epilepsy
• Tourette's syndrome
• Learning difficulties, often including dyslexia

ADHD is one of the more, if not the most, researched areas in child and adolescent mental health. The precise cause of the disorder remains unknown, despite these efforts, although a lot of available evidence suggests that ADHD is, as a brain-based biological disorder, genetic. This includes observations of low levels of dopamine found in children with ADHD. And brain imaging studies using PET scans have found that brain metabolism in children with ADHD is lower in the areas of the brain believed to be responsible for attention, social judgement, and movement.

While genetics are expected to be the largest indicator of ADHD—with four out of three children with ADHD having a relative with the disorder—there have been other factors considered to contribute to the development of ADHD:

• Those who were born prematurely (before the 37th week of pregnancy) or with a low birthweight
• Those born with epilepsy
• Those with brain damage, whether it occurs in the womb or after a sever head injury later in life
• A mother smoking, using alcohol, or having extreme stress during pregnancy

Like many disorders, ADHD is largely considered to be caused by, in addition to genetics, a combination factors. Researchers have investigated possible environmental factors, such as brain injuries, nutrition, and social environments, and how these may or may not play a role in ADHD.

However, this research has not supported more popularly held views that ADHD has been caused by eating too much sugar, watching too much television, parenting, or social or environmental factors such as poverty or family chaos. That said, many of these factors, and others not accounted for, can make symptoms of ADHD worse. But there is no evidence strong enough to conclude these are the main causes, or even partial causes, of ADHD.

Although children are often recommended to seek diagnosis for a child who is considered to possibly be suffering from ADHD, concerned parents still have to seek a diagnosis from healthcare providers. These providers, in turn, use guidelines from the American Psychiatric Association's Diagnostic and Statistical Manual, fifth edition (DSM-5), to help diagnose ADHD. Most often, these parents are directed towards a psychiatrist for testing and diagnosis. Using a single standard, especially across different communities, helps determine how many people have ADHD, and how public health is impacted by ADHD.

In confirming a diagnosis, a person often takes a battery of tests to check symptoms and their neurological or psychological status. These tests are given by a psychiatrist, pediatrician, or mental health provider with experience in diagnosing and treating ADHD. Often a primary care physician will refer an individual or a child's parents to a specialist for those tests. Tests may include the following:

• A medical and social history of both the child and the family
• A physical exam and neurological assessment that often involves screening of vision, hearing, verbal, and motor skills
• An evaluation of intelligence, aptitude, personality traits, or processing skills
• A scan called the Neuropsychiatric EEG-Based Assessment Aid (NEBA) System, which measures theta and beta brain waves, which have been shown to be higher in children and adolescents with ADHD than in children without ADHD

The DSM-5 criteria for ADHD requires that people with ADHD show a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development. This means at least six or more symptoms of inattention, as described above, for children up to age sixteen years, or five or more symptoms for adolescents age seventeen years and older and adults have to be observed. And, further, those symptoms have to be present for at least six months, and have to be considered inappropriate for the individual's developmental level.

For hyperactivity and impulsivity, a similar six or more symptoms from those described above have to be observed in children up to the age of sixteen years, while five or more are expected to be observed for adolescents age seventeen years and older and adults. Symptoms of hyperactivity-impulsivity have to have been observed to be present for at least six months to an extent that is disruptive and can be considered inappropriate for a person's developmental level.

In addition, there are following conditions which are required to be met for diagnosis:

• Several inattentive or hyperactive-impulsive symptoms were present before the age of twelve years old
• Several symptoms are present in two or more settings
• There is clear evidence that the symptoms interfere with, or reduce the quality of, social, school, or work functioning
• The symptoms are not better explained by another mental disorder (such as a mood disorder, anxiety disorder, dissociative disorder, or a personality disorder). The symptoms also cannot happen during the course of schizophrenia or another psychotic disorders

Dependent on the symptoms, the person's ADHD can be classified into three types of presentations, being the combined presentation, the predominantly inattentive presentation, and predominantly hyperactive-impulsive presentation.

There is no cure for ADHD, and available treatments work mainly to reduce the symptoms of ADHD and improve the functioning of the person with ADHD. These treatments include medication, psychotherapy, education or training, or a combination of treatments.

Medications are the most common way of treating ADHD and can affect children differently while having side effects such as decreased appetite or sleep problems. These medications reduce hyperactivity and impulsivity and can improve the ability to focus, work, and learn. Sometimes several different medications or dosages need to be tried before finding the right dosage and medication for a particular person.

The AAP recommends that, in determining the correct medication and dosage, healthcare providers observe and adjust the doses to find the right balance between benefits and side effects. It is also important for parents to work with their child's healthcare providers to find the medications that work best for their child. There are generally two types of medications used for treating ADHD. The most common is stimulants, while lesser used medications are classified as non-stimulants.

Stimulant therapy is the most common used treatment for ADHD; they have been found to be an effective way of managing symptoms such as short attention span, impulsive behavior, and hyperactivity. These can be used alone, or in combination with behavior therapy. These drugs improve ADHD symptoms in around 70 percent of adults and 70 to 80 percent of children after starting treatment.

Improvements from these therapeutics include reduced interrupting, fidgeting, and hyperactive symptoms, as well as improved task completion and home relationships. Improvements in behavior and attention span often continue as long as the medication is taken, while benefits in social adjustment and school performance have not been shown to endure over the long term.

These medications have not been considered habit forming when treating ADHD in children and adolescents, and there has been little to no evidence that the use of ADHD medications lead to drug abuse. However, there is still considered to be the potential for abuse and addiction with any stimulant medication, especially in the case of a person with a history of substance abuse. Recent research has, nevertheless, shown that individuals with ADHD had a lower incidence of substance use disorder if they were medically treated than if they were not treated.

There are many stimulants available: short acting, or immediate release; intermediate acting; and long-acting forms. The short-acting forms of the drug are usually taken two or three times a day while long-acting ones are taken once a day. Newer forms of some drugs may reduce side effects and relieve symptoms for a longer period of time. These include Concerta (10 to 12 hour duration), Ritalin LA (6 to 8 hours), Metadate CD (6 to 8 hours), and Adderall XR (10 to 12 hours), Vyvanse (up to 13 hours), Focalin XR (12 hours), and Daytrana (10 to 12 hours).

There are other medications for ADHD which are non-stimulants. These medications take longer to start working that non-stimulants, but can also improve focus, attention, and impulsivity in a person with ADHD. These medications can be prescribed when a person has difficult side effects from stimulants, when a stimulant is not effective, or in combination with a stimulant to increase effectiveness.

Although not approved by the U.S. Food and Drug Administration (FDA) for the treatment of ADHD, some antidepressants can be used alone or in combination with a stimulant to treat ADHD. Antidepressants can help all of the symptoms of ADHD and can also be prescribed to alleviate the side effects of stimulant medications. Antidepressants can also be used in combination with stimulants if a patient also has another condition, such as an anxiety disorder, depression, or another mood disorder. Non-stimulant ADHD medications and antidepressants may also have side effects.

Examples of some non-stimulant medications for ADHD include atomoxetine, such as Strattera; clonidine, including Catapres or Kapvay; and guanfacine, such as Intuniv.

There are several psychosocial interventions that have been shown to help individuals with ADHD and their families manage symptoms and improve everyday functioning. For school-age children, often there is a buildup of frustration, blame, and anger in a family prior to the child being diagnosed. The parents and the child in this case often need specialized help to overcome those feelings. Meanwhile, a mental health professional can help educate parents about ADHD and the effects it can have on a family. They can also help the child and the parents develop skills, attitudes, and ways of relating to each other to help alleviate symptoms and improve functioning.

All types of therapy for children and teens with ADHD require the parents to play an active role. Psychotherapy that only treats the child, without the involvement of a parent, cannot effectively manage ADHD symptoms or behavior, especially as the symptoms and behaviors can be a response to the way the parents are acting, or can be exacerbated by a parent's behavior. With ADHD being a genetic condition, often a parent can be undiagnosed or have some symptoms similar to the child.

Behavioral therapy is a type of psychotherapy that works to help a person change their behavior. This can involve practical assistance, such as help organizing tasks or completing schoolwork, or working through emotionally difficult events. This type of therapy can also teach a person how to monitor their own behavior and give oneself praise or rewards for acting in a desired way.

Parents, teachers, and family members also can give feedback on behaviors and help establish clear rules, lists, and structured routines to help individuals control their behaviors. Therapists can also teach children social skills, such as waiting their turn, sharing toys, asking for help, or responding to teasing. Learning to read facial expressions and the tone of voice in others can also be an important part of this kind of therapy.

Cognitive behavioral therapy can help a person learn how to be aware of and accepting one's own thoughts and feelings to improve focus and concentration. The therapist can also encourage the person with ADHD to adjust to life changes which come with treatment, such as thinking before acting or resisting an urge to take unnecessary risks.

This therapy can help family members and spouses work to find productive ways to handle disruptive behaviors from a child with ADHD and work to encourage behavior changes while improving interactions overall with children and people with ADHD.

Similar to family and marital therapy, and also known as behavioral parent management training, parenting skills training works to teach parents for encouraging and rewarding positive behaviors in children with ADHD. Parents are often taught to use a system of rewards and consequences to encourage a change in a child's behavior, and are taught to give immediate and positive feedback for behaviors they want to encourage, and to ignore or redirect behaviors they want to discourage.

Specific behavioral classroom management interventions and academic accommodations for children and teens with ADHD have been used and shown to be effective for managing symptoms and improving functioning at school and with peers. Interventions can include behavior management plans or teaching organizational or study skills, while accommodations may include preferential seating in the classroom, reduced classwork load, or extended time on tests and exams. The school may also provide accommodations through what is known as a 504 Plan, or, for children who qualify for special education services, an Individualized Education Plan (IEP).

The effects of ADHD upon children and their families change as the child ages and moves through preschool years to primary school and into adolescence, with varying aspects of the disorder being more prominent at different stages. As well, ADHD has been known to persist into adulthood where it can cause disruptions to an individual's professional and personal life. ADHD has been associated with increased healthcare costs for individuals and their family's.

Studies undertaken to better understand the longer term effects on individuals with ADHD found that out of 232 children with ADHD at a mean age of 10.4 years, at around age 27 about one third or 29.3 percent fulfilled the criteria for adult ADHD. This same study found that the persistence rate for males and females is consistent, with 29.3 and 29.2 percent respectively. A ten-year follow-up study found that of 110 boys diagnosed with ADHD when aged six to seventeen that 78 percent of the boys continued to have full or partial persistent ADHD symptoms into adulthood. The researchers in this study defined persistence as meeting full DSM-IV criteria for ADHD and partial persistence as failing to attain functional remission or receiving treatment of ADHD.

Of the 78 percent who had ADHD symptoms, about 35 percent continued to meet the full DSM-IV criteria for ADHD, while 22 percent had subsyndromal ADHD, and about 15 percent had impaired functioning while a further 6 percent were in remission while still being treated.

A follow-up study of 140 boys with ADHD found them to be significantly more impaired in psychosocial, educational, and neuropsychological functioning when compared to those with ADHD. While an 11-year follow-up study of 140 girls diagnosed with ADHD at ages six to eighteen found that 62 percent of girls continued to have impairing ADHD symptoms as young adults. These girls were found to have a significantly higher risk for antisocial disorders, major depression, and anxiety disorders as adults when compared to girls without ADHD.

Further studies found that, when compared, treated ADHD versus untreated ADHD in 48 studies with 78 outcomes saw treatment of ADHD resulted in favorable outcomes for most outcomes reported. This saw treatment of ADHD resulting in improvement compared with participants with untreated ADHD, improvement compared with a pretreatment baseline, and improvement in stabilization when compared with a pretreatment baseline. This included less non-medicinal drug use or addictive behavior, better academic performance and achievements, less antisocial behavior, better social function, better occupation and occupation history, better self-esteem, compared to pretreatment baselines and compared to untreated ADHD.

In the studies into long term effects of ADHD on an individual, they found that 32.2 percent of students with the combined presentation of ADHD dropped out of high school, compared to only 15 percent of adolescents without a known psychiatric disorder. And of college students, between 2 percent to 8 percent of college students have been estimated to have ADHD.

The National Center for Education Statistics estimates that in 2012 there were approximately 20 million students enrolled in college. This meant that, if the estimated percentages of the population had ADHD, between 412,000 to 1.6 million students with ADHD enrolled in college in 2012. A study by Kuriyan et al. (2013) into young adults diagnosed with ADHD showed the following:

• Individuals with ADHD were far less likely to enroll in a four-year college course
• Individuals with ADHD were eleven times more likely to not enroll in any school vs. enrolling in a four-year college course
• Fifty percent of students with ADHD attended vocational or junior colleges vs.18 percent of the non-ADHD comparison group
• Fifteen percent of young adults with ADHD held a 4-year degree compared to 48 percent of the control group
• 0.06 percent of young adults with ADHD held a graduate degree compared to 5.4 percent of the control group

The same study by Kuriyan et al. (2013) also investigated the occupational outcomes for young adults with ADHD between the ages of 23 and 32. The study showed the following for young adults with ADHD:

• They were eleven times more likely to be unemployed and not in school
• They were times more likely to be in unskilled vs. clerical occupation, and six times more likely to be in unskilled vs. a professional occupations
• Sixty-one percent were found to be more likely to have been fired, compared to only 43 percent in the comparison group
• Thirty-three percent more likely to have been laid off, compared to 13 percent of the comparison group
• Fifty-three percent were found more likely to have quite a job due to dislike, compared to 36 percent of the comparison group
• Earning close to $2 per hour less in wages than the comparison group

The benefit of treated ADHD versus untreated ADHD are fairly clear, where individuals able to get their ADHD under control are able to perform better in society and often report higher levels of self-esteem. However, the drugs come with some risks, and as part of the treatment of ADHD a physician and an individual have to work and find the appropriate medication, in terms of effectiveness and possible side effects. The following are some side effects and risks associated with the long-term use of ADHD medication:

• Heart disease
• High blood pressure
• Seizure
• Irregular heartbeat
• Abuse and addiction
• Appetite suppression
• Skin discolorations

ADHD and executive functions and related detriments are linked, but not necessarily synonymous. People without ADHD, can have executive functioning strengths and challenges that affect their abilities to pay attention, to learn, at work, and in relationships. However, for those with ADHD, executive function challenges are often more severe and more numerous than those without it. There are seven major types of self-regulation associated with executive functioning:

• Self-awareness—commanding self-directed attention
• Self-restraint—inhibiting oneself
• Non-verbal working memory—holding things in one's mind to guide behavior
• Verbal working memory—retaining internal speech
• Emotional—using words and images along with self-awareness to alter how one feels about things
• Self motivation—motivating oneself to do things when no outside consequences exist
• Planning and problem solving—finding new approaches and solutions

Executive functions begin developing by the age of two and are only fully developed at the age of thirty. People with ADHD are 30 to 40 percent delayed in development, which makes them more likely to act motivated by short-term rather than longer-term goals. People with executive functioning challenges or ADHD may experience impairments in touch memory, planning, emotional, regulation, or social skills. There are specific executive functions that tend to be impaired in individuals with ADHD:

• Activation—organizing tasks and materials, estimating time, getting started
• Focus—finding, sustaining, and shifting attention as needed
• Effort—regulating alertness, sustaining motivation, and processing speed
• Emotion—managing frustration and modulating feelings
• Memory: using working memory and accessing recall
• Action: monitoring and regulating physical activity

Theories have increasingly highlighted the role of executive function impairments in individuals with ADHD, where impairments in these functions can lead to poor attention and planning, difficulties generating and implementing strategies, inability to utilize feedback, and inflexibility of thinking. Poor performance on executive function tasks are often associated with abnormalities in the prefrontal cortex and associated subcortical and posterior structures. Moreover, neuroimaging has revealed deficits in neural activity within the fronto-striatal and front-parietal circuits of individuals with ADHD. And meta-analyses studies have provided evidence of a consistent pattern of hypoactivation in frontal brain regions of individuals with ADHD compared with controls.

Research into these theories and associated links with individuals with ADHD have emphasized impairments in inhibitory control and working memory. One model of ADHD emphasized inhibitory control, or the inhibition of prepotent response, stopping an ongoing response, and interference control, as the primary neuropsychological impairments that can underlie secondary impairments in working memory and related functions.

However, working memory, a limited capacity system that temporarily stores and manipulates information while performing complex tasks, has also been proposed as a "core" deficit in ADHD. According to the functional working model of ADHD, inhibition is a downstream product of the working memory as stimuli must gain access to this system before a response can be inhibited. Furthermore, research has indicated that working memory is important for learning and acquiring academic skills. This has likely been due to working memory having an impact on many activities that have been associated with success in classroom learning, including remembering instructions or keeping track of progress on complex tasks. These working memory deficits have been linked to learning problems and poor school performance in children with and without ADHD.