Everybody can have difficulty sitting still, paying attention or controlling impulsive behavior once in a while. For some people, however, the problems are so pervasive and persistent that they interfere with every aspect of their life: home, academic, social and work.
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting 11 percent of school-age children. Symptoms continue into adulthood in more than three-quarters of cases. ADHD is characterized by developmentally inappropriate levels of inattention, impulsivity and hyperactivity.
Individuals with ADHD can be very successful in life. However, without identification and proper treatment, ADHD may have serious consequences, including school failure, family stress and disruption, depression, problems with relationships, substance abuse, delinquency, accidental injuries and job failure. Early identification and treatment are extremely important.
Medical science first documented children exhibiting inattentiveness, impulsivity and hyperactivity in 1902. Since that time, the disorder has been given numerous names, including minimal brain dysfunction, hyperkinetic reaction of childhood, and attention-deficit disorder with or without hyperactivity. With the Diagnostic and Statistical Manual, Fifth Edition (DSM-5) classification system, the disorder has been renamed attention-deficit/hyperactivity disorder or ADHD. The current name reflects the importance of the inattention aspect of the disorder as well as the other characteristics of the disorder such as hyperactivity and impulsivity.
Typically, ADHD symptoms arise in early childhood. According to the DSM-5, several symptoms are required to be present before the age of 12. Many parents report excessive motor activity during the toddler years, but Attention-deficit/hyperactivity disorder symptoms can be hard to distinguish from the impulsivity, inattentiveness and active behavior that is typical for kids under the age of four. In making the diagnosis, children should have six or more symptoms of the disorder present; adolescents 17 and older and adults should have at least five of the symptoms present. The DSM-5 lists three presentations of ADHD—Predominantly Inattentive, Hyperactive-Impulsive and Combined. The symptoms for each are adapted and summarized below.
ADHD predominantly inattentive presentation
- Fails to give close attention to details or makes careless mistakes
- Has difficulty sustaining attention
- Does not appear to listen
- Struggles to follow through with instructions
- Has difficulty with organization
- Avoids or dislikes tasks requiring sustained mental effort
- Loses things
- Is easily distracted
- Is forgetful in daily activities
ADHD predominantly hyperactive-impulsive presentation
- Fidgets with hands or feet or squirms in chair
- Has difficulty remaining seated
- Runs about or climbs excessively in children; extreme restlessness in adults
- Difficulty engaging in activities quietly
- Acts as if driven by a motor; adults will often feel inside as if they are driven by a motor
- Talks excessively
- Blurts out answers before questions have been completed
- Difficulty waiting or taking turns
- Interrupts or intrudes upon others
ADHD combined presentation
- The individual meets the criteria for both inattention and hyperactive-impulsive ADHD presentations.
These symptoms can change over time, so children may fit different presentations as they get older.
Confusing labels for ADHD
In 1994, the name of the disorder was changed in a way that is confusing for many people. Since that time all forms of attention deficit disorder are officially called “Attention-Deficit/Hyperactivity Disorder,” regardless of whether the individual has symptoms of hyperactivity or not. Even though these are the official labels, a lot of professionals and lay people still use both terms: ADD and ADHD. Some use those terms to designate the old subtypes; others use ADD just as a shorter way to refer to any presentation.
Severity of symptoms
As ADHD symptoms affect each person to varying degrees, the DSM-5 now requires professionals diagnosing ADHD to include the severity of the disorder. How severe the disorder is can change with the presentation during a person’s lifetime. Clinicians can designate the severity of ADHD as “mild,” “moderate” or “severe” under the criteria in the DSM-5.
- Mild: Few symptoms beyond the required number for diagnosis are present, and symptoms result in minor impairment in social, school or work settings.
- Moderate: Symptoms or functional impairment between “mild” and “severe” are present.
- Severe: Many symptoms are present beyond the number needed to make a diagnosis; several symptoms are particularly severe; or symptoms result in marked impairment in social, school or work settings.
As individuals age, their symptoms may lessen, change or take different forms. Adults who retain some of the symptoms of childhood ADHD, but not all, can be diagnosed as having ADHD in partial remission.
ADHD throughout the lifespan
Children with ADHD often experience delays in independent functioning and may behave younger than their peers. Many children affected by ADHD can also have mild delays in language, motor skills or social development that are not part of ADHD but often co-occur. They tend to have low frustration tolerance, difficulty controlling their emotions and often experience mood swings.
Children with ADHD are at risk for potentially serious problems in adolescence and adulthood: academic failure or delays, driving problems, difficulties with peers and social situations, risky sexual behavior, and substance abuse. There may be more severe negative behaviors with co-existing conditions such as oppositional defiant disorder or conduct disorder. Adolescent girls with ADHD are also more prone to eating disorders than boys. As noted above, ADHD persists from childhood to adolescence in the vast majority of cases (50–80 percent), although the hyperactivity may lessen over time.
Teens with ADHD present a special challenge. During these years, academic and life demands increase. At the same time, these kids face typical adolescent issues such as emerging sexuality, establishing independence, dealing with peer pressure and the challenges of driving.
More than 75 percent of children with ADHD continue to experience significant symptoms in adulthood. In early adulthood, ADHD may be associated with depression, mood or conduct disorders and substance abuse. Adults with ADHD often cope with difficulties at work and in their personal and family lives related to ADHD symptoms. Many have inconsistent performance at work or in their careers; have difficulties with day-to-day responsibilities; experience relationship problems; and may have chronic feelings of frustration, guilt or blame.
Individuals with ADHD may also have difficulties with maintaining attention, executive function and working memory. Recently, deficits in executive function have emerged as key factors affecting academic and career success. Executive function is the brain’s ability to prioritize and manage thoughts and actions. This ability permits individuals to consider the long-term consequences of their actions and guide their behavior across time more effectively. Individuals who have issues with executive functioning may have difficulties completing tasks or may forget important things.
More than two-thirds of children with ADHD have at least one other co-existing condition. Any disorder can co-exist with ADHD, but certain disorders seem to occur more often. These disorders include oppositional defiant and conduct disorders, anxiety, depression, tic disorders or Tourette syndrome, substance abuse, sleep disorders and learning disabilities. When co-existing conditions are present, academic and behavioral problems, as well as emotional issues, may be more complex.
These co-occurring disorders can continue throughout a person’s life. A thorough diagnosis and treatment plan that takes into account all of the symptoms present is essential.
Despite multiple studies, researchers have yet to determine the exact causes of ADHD. However, scientists have discovered a strong genetic link since ADHD can run in families. More than 20 genetic studies have shown evidence that ADHD is strongly inherited. Yet ADHD is a complex disorder, which is the result of multiple interacting genes.
Other factors in the environment may increase the likelihood of having ADHD:
- exposure to lead or pesticides in early childhood
- premature birth or low birth weight
- brain injury
Scientists continue to study the exact relationship of ADHD to environmental factors, but point out that there is no single cause that explains all cases of ADHD and that many factors may play a part.
Previously, scientists believed that maternal stress and smoking during pregnancy could increase the risk for ADHD, but emerging evidence is starting to question this belief. However, further research is needed to determine if there is a link or not.
The following factors are NOT known causes, but can make ADHD symptoms worse for some children:
- watching too much television
- eating sugar
- family stress (poverty, family conflict)
- traumatic experiences
ADHD symptoms, themselves, may contribute to family conflict. Even though family stress does not cause ADHD, it can change the way the ADHD presents itself and result in additional problems such as antisocial behavior.
Problems in parenting or parenting styles may make ADHD better or worse, but these do not cause the disorder. Attention-deficit/hyperactivity disorder is clearly a brain-based disorder. Currently research is underway to better define the areas and pathways that are involved.