Identifying Attention Deficit Hyperactivity Disorder

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) At one time or another, we've all encountered a child whose challenging, sometimes bizarre behavior leaves us puzzling over what's going on in the young person's head.
Perhaps at the grocery store, we've watched a frustrated parent call an errant child's name repeatedly and implored him or her to "put that down" and "don't touch that" and "keep your hands to yourself." Maybe there was a child at school who couldn't seem to sit still and was in constant motion. Maybe the child appeared always to be daydreaming in class or couldn't focus on any task long enough to finish it. Perhaps, we tell ourselves, the child is bored or the task to easy, so it's natural the student wants to move on to something else.

Attention deficit hyperactivity disorder (ADHD) has many faces and remains one of the most talked-about and controversial topics in parenting and education. Hanging in the balance of heated debates over medication, diagnostic methods and treatment options are children, adolescents and adults who must each day manage the condition and lead productive lives. To help parents, caregivers, teachers, school administrators and others better understand this mental health condition, the U.S. Department of Education, with the assistance of its Office of Special Education and Rehabilitative Services and Office of Special Education Programs, have put together some vital information for everyone who interacts with a person diagnosed with or displaying symptoms of ADHD.

ADHD Defined and Described

This neurological condition involves problems with inattention and hyperactivity-impulsivity that are developmentally inconsistent with the age of the child. Research has increasingly shown that ADHD is not a disorder of attention; instead, it's a function of developmental failure in the brain circuitry that monitors inhibition and self-control. This loss of self-regulation impairs other important brain functions crucial for maintaining attention, including the ability to defer immediate rewards for later gain.

Children with ADHD can also exhibit excessive motor activity. The high energy level and subsequent behavior are often misperceived as purposeful noncompliance when, in fact, they may be a manifestation of the disorder that requires specific interventions.

What makes this condition so confounding is that children with ADHD can exhibit a range of symptoms and levels of severity. Additionally, many children with ADHD often are of average intelligence and have a range of personality characteristics and individual strengths.

The typically behavior associated with ADHD is classified into two main categories: poor sustained attention and hyperactivity-impulsiveness. As a result of the range of behaviors children with the condition can exhibit, three subtypes of the disorder appear in the fourth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders:

  • ADHD predominantly inattentive (ADHD-PI or ADHD-I)
  • ADHD predominantly hyperactive-impulsive (ADHD-PHI)
  • ADHD combined (ADHD-C)

A child expressing hyperactivity commonly appears fidgety, has trouble staying seated or playing quietly and acts as if driven by a motor. Children displaying impulsivity often have difficulty participating in tasks that require taking turns. Other common behaviors of ADHD may include blurting out answers to questions instead of waiting to be called on and flitting from one task to another without finishing.

The inattention component of ADHD affects the educational experience of these children because ADHD makes it difficult for them to attend to detail in directions, sustain attention for the duration of a task and misplace needed items. These children often fail to give close attention to details, make careless mistakes and avoid or dislike tasks requiring sustained mental effort. Children with ADHD may also experience difficulty in reading, math and written communication. Although these behaviors are not in themselves a learning disability, almost one-third of all children with ADHD have learning disabilities, according to the National Institute of Mental Health.

Furthermore, ADHD commonly occurs with other conditions: Research suggests that approximately 40 to 60 percent of children with ADHD have at least one coexisting disability. Although any disability can coexist with this mental health condition, certain disabilities seem to be more common than others. In addition to learning disabilities, the more common condition coinciding with ADHD include disruptive behavior disorders, mood disorders, anxiety disorders and tics and Tourette's syndrome.

ADHD affects children differently at different ages. In some cases, children initially identified as having ADHD-PHI are subsequently identified as having ADHD-C as their attention problems surface.

The characteristics of this disorder affect not only children's academic lives but often their social lives as well. Children with ADHD-PHI may show aggressive behaviors, while children with ADHD-PI may be more withdrawn. Because they're less disruptive than children with ADHD who are hyperactive or impulsive, many children diagnosed with ADHD-PI go unrecognized and unassisted. Both types of children with ADHD may be less cooperative with other children and adults, and they may be less willing to wait their turn or play by the rules. Because they're unable to control their own behavior, they may experience social isolation. Consequently, their self-esteem may suffer.

In the U.S., an estimated 1.46 to 2.46 million children--that's 3 to 5 percent of the student population--have ADHD, per the American Psychiatric Association. Boys are four to nine times more likely to be diagnosed with the condition, and the disorder is found in all cultures, although prevalence figures differ.

The Causes of ADHD

ADHD has traditionally been viewed as a problem related to attention, stemming from an inability of the brain to filter competing sensory inputs, such as sight and sound. Recent research, however, has shown that children with ADHD don't have difficulty in that area. Instead, researchers now believe children with ADHD can't control their impulsive motor responses to such input.

Although the direct and immediate causes of ADHD are still unclear, advances in neurological imaging techniques and genetics are helping to clarify this issue. Most researchers suspect the cause of ADHD is genetic or biological, although they acknowledge a child's environment does help determine specific behaviors.

Imaging studies conducted during the past decade have indicated which brain regions may malfunction in patients with ADHD, thus accounting for the condition's symptoms. A 1996 National Institutes for Mental Health study found the right prefrontal cortex (part of the cerebellum) and at least two of the clusters of nerve cells known collectively as the basal ganglia are significantly smaller in children with ADHD: These areas of the brain seem to relate to the regulation of attention. Why these areas of the brain are smaller for some children is unknown, but researchers have suggested mutations in several genes active in the prefrontal cortex and basal ganglia may play a significant role.

In addition, other factors not related to genes have been linked to ADHD. They include premature birth, maternal alcohol and tobacco use, high levels of lead exposure and prenatal neurological damage. Although some people claim food additives, sugar, yeast and even poor parenting methods lead to ADHD, there's no conclusive evidence to support these beliefs.

Diagnosing ADHD

Although toddlers and preschoolers may show characteristics of ADHD, some of these behaviors may be normal for their age or developmental stage. Instead, a child must exhibit the behaviors associated with ADHD to an abnormal degree to warrant identification as ADHD. Even with older children, other factors, including environmental influences, can produce behaviors resembling ADHD.

The criteria set forth by the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders are used as the standardized clinical definition to determine the presence of ADHD. A person must exhibit several of the following characteristics to be clinically diagnosed with ADHD:

  • Severity -- The behavior in question must occur more frequently in the child than in other children at the same developmental stage
  • Early onset -- At least some of the symptoms must have been present prior to age 7
  • Duration -- The symptoms must also have been present for at least six months prior to the evaluation
  • Impact -- The symptoms must have a negative impact on the child's academic or social life
  • Settings -- The symptoms must be present in multiple settings

Additionally, according to the Diagnostic and Statistical Manual of Mental Disorders, a person with ADHD must meet these criteria:

  • Six or more specific symptoms of inattention or six or more specific symptoms hyperactivity-impulsivity that have persisted for at least six months to a degree that is maladaptive and inconsistent with developmental level
  • Some hyperactive-impulsive or inattentive symptoms that caused impairment were present before age 7
  • Some impairment from the symptoms is present in two or more settings (for example, at school and at home)
  • There must be clear evidence of clinically significant impairment in social, academic or occupational functioning.
  • The symptoms do not occur exclusively during the course of a pervasive developmental disorder (autism, Asperger's syndrome, childhood disintegrative disorder, Rett's syndrome, pervasive development disorder not otherwise specified), schizophrenia or other psychotic disorder and are not better accounted for by another mental disorder (for example, mood disorder, anxiety disorder, disassociative disorder or a personality disorder)

The specific criteria for diagnosing ADHD according to the Diagnostic and Statistical Manual of Mental Disorders are available on the Center for Disease Control and Prevention's Web site.

Diagnosing a child with ADHD can take time, and the process can try the patience of parents who want to help their struggling young one. But it's important to remember the diagnostic criteria are in place to help prevent misdiagnoses, which can lead to needless and potentially harmful medications and costly, inappropriate therapies--in other words, to safeguard a young life.

Reviewed by: 
Review Date: 
September 21, 2010
Last Updated:
February 16, 2011