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ATTENTION DEFICIT HYPERACTIVITY DISORDER OVERVIEW — Attention deficit hyperactivity disorder (ADHD) is a medical condition with symptoms of inattention, hyperactivity, and impulsivity. It is often first recognized in childhood. The symptoms affect a child's cognitive, academic, behavioral, emotional, and social functioning, and the condition often continues into adulthood.
Approximately 8 to 10 percent of children aged 4 to 17 years have ADHD, making it one of the most common disorders of childhood. It occurs two to four times more commonly among males, particularly the symptoms of hyperactivity and impulsivity.
The symptoms and diagnosis of ADHD will be reviewed here. The treatment of ADHD is discussed separately. (See "Patient education: Treatment of attention deficit hyperactivity disorder in children (Beyond the Basics)".)
ADHD CAUSES — The cause(s) of ADHD are not clear, although there are a number of theories. Most experts agree that ADHD is a medical or neurodevelopmental disorder. Many experts believe there is an inherited imbalance of chemicals in the brain. This is supported by the improvements often seen with the use of medications that affect these chemicals.
Exposure to tobacco before birth may increase the risk of developing ADHD. Most experts do not feel that dietary factors (food additives, sugar, food sensitivity, mineral deficiency) cause ADHD. It is possible that some children have mild changes in behavior and attention in response to certain foods or food additives. However, these changes do not meet the diagnostic criteria for ADHD. (See 'Diagnostic criteria' below.)
ADHD SYMPTOMS — ADHD is a condition that can cause three categories of symptoms: hyperactivity, impulsivity, and inattention. Children with ADHD may have one or more of these symptoms, and the symptoms may change in frequency or pattern as the child develops. In most situations, the child has difficulty controlling their behavior or attention and may have difficulty anticipating the consequences of their behavior. The child does not usually misbehave because they are willful or wants to annoy those around them.
Hyperactivity — Hyperactive behavior is defined as excessive fidgetiness or talking, difficulty remaining seated when required to do so, difficulty playing quietly, and frequent restlessness or always seeming to be "on the go."
These symptoms are usually seen by the time a child is four years old and typically increase over the next three to four years. The symptoms may peak in severity when the child is seven to eight years of age, after which they often begin to decline. By the adolescent years, the hyperactive symptoms may be less noticeable, although ADHD can continue to be present.
Impulsivity — Impulsive behavior almost always occurs with hyperactivity in younger children. It can cause difficulty waiting turns, blurting out answers too quickly, disruptive classroom behavior, intruding or interrupting others' activities, rejection by classmates, and unintentional injury.
Similar to the hyperactive symptoms, impulsive symptoms are typically seen by the time a child is four years old and increase during the next three to four years to peak in severity when the child is seven to eight years of age. However, impulsive symptoms usually continue to be a problem throughout the life of the individual.
Inattention — Inattention may take many forms, including forgetfulness, being easily distracted, losing or misplacing things, disorganization, underachievement in school, poor follow-through with assignments or tasks, poor concentration, and poor attention to detail.
Because of the developmental demands on a child (eg, needing to pay attention, sit still), these problems may become more obvious in school when the child is eight to nine years old, although the child may have symptoms at a younger age when at home. Inattention is most likely to persist through adolescence and potentially into adulthood.
Types of ADHD — Three subtypes of ADHD have been identified:
●The predominantly inattentive type, previously known as attention deficit disorder
●The predominantly hyperactive-impulsive type
●The combined type
The subtype is determined based upon a child's predominant symptoms and can change over time.
ADHD EVALUATION AND DIAGNOSIS — Caregivers who are concerned their child may have ADHD should speak with the child's health care provider. Early recognition and treatment of ADHD are important to prevent or limit emotional, academic, and behavioral difficulties.
There is no simple test to diagnose ADHD. In addition, many of the symptoms of ADHD are common among four- to six-year-old children but tend to occur with less frequency and/or intensity than in children with ADHD. Thus, it may be difficult for caregivers to tell if their young child has ADHD or is simply behaving as young children often do. A child who is young for their grade may act less mature than a child who is at the older end of the spectrum; this does not necessarily indicate a problem, and it is important for clinicians to be careful to stick to the diagnostic criteria (below) in their evaluation. Studies that evaluate children over time have confirmed that most preschool children who meet all the criteria for ADHD will continue to do so as they get older.
It can also be difficult to diagnose ADHD in older children and teens. There is some evidence that frequent digital media use (eg, spending a lot of time on social media or playing video games) can lead to symptoms like difficulty focusing. While this is still being studied, it may be an explanation for ADHD symptoms that develop during adolescence.
Diagnostic criteria — Criteria for the diagnosis of ADHD have been defined by the American Psychiatric Association. There are several important features of these criteria, including the following:
●The symptoms must be present in more than one setting (eg, school and home)
●The symptoms must persist for at least six months
●The symptoms must be present before the age of 12 years
●The symptoms must impair function in academic, social, or occupational activities
●The symptoms must be excessive for the age of the child
●Other mental disorders that could account for the symptoms must be excluded
There are a number of other medical and psychologic conditions that have symptoms similar to those of ADHD. A thorough medical, developmental, educational, and psychosocial evaluation is necessary to confirm the diagnosis. Several office visits, occasionally with more than one health care provider, may be necessary during the evaluation process.
CONDITIONS THAT EXIST WITH ADHD — Other psychologic and developmental disorders exist in as many as one-half of children with ADHD. These can be difficult to distinguish from ADHD because there are frequently overlapping symptoms. The most common coexisting disorders include learning disabilities, disruptive behavior disorders (oppositional defiant disorder [ODD] and conduct disorder [CD]), anxiety, and mood disorders (depression or bipolar disorder). ADHD can also co-occur with autism spectrum disorder.
Treatment for coexisting conditions may require medication. Behavioral or psychosocial treatments may also be recommended. A child with a coexisting condition usually requires the care of a specialist (eg, psychiatrist, child psychologist or developmental behavioral pediatrician, pediatric neuropsychologist, pediatric neurologist).
Learning disorders — Learning disorders occur in 20 to 50 percent of children with ADHD and may cause difficulty with performance in school. Caregivers should consult with the child's teacher and/or school counselor if they child is demonstrating difficulty with reading, spelling, or arithmetic.
Disruptive behavior disorders — Disruptive behavior disorders include ODD and CD, and affect up to 40 percent of people with ADHD. While all children and adolescents can exhibit disruptive behaviors at some point, those with ODD or CD behave in this way frequently and over a longer period of time than would normally be expected.
ODD often causes a pattern of arguing with adults, frequent temper tantrums, and refusing to follow rules at school or home. CD is a more severe form of ODD that includes a pattern of intentionally breaking the rules while trying to avoid being caught; lying or stealing; and aggressive behaviors that threaten or harm property, people, or animals.
Anxiety and mood disorders — Anxiety and mood disorders include depression, anxiety, and bipolar (manic depressive) disorder. (See "Patient education: Depression in children and adolescents (Beyond the Basics)" and "Patient education: Bipolar disorder (Beyond the Basics)".)
WHEN TO SEEK HELP — Caregivers who suspect that their child has ADHD should begin by talking to the child's teacher and/or school staff. This can help caregivers determine if the child has difficulties with behavior in more than one setting (eg, at home and at school).
The next step is to make an appointment with the child's health care provider. The provider will evaluate the child and determine if further testing or evaluation is needed, and if ADHD or another condition is a possible cause of symptoms. Bringing school records to the appointment may help the provider to have a clearer understanding of the child's situation. More than one visit, occasionally with another clinician, is often necessary before a diagnosis is made.
After the diagnosis is made and treatment begins, the caregiver, teacher, and health care provider will continue to monitor the child to ensure that treatment is effective and the diagnosis is correct. Referral to a developmental behavioral pediatrician or child psychiatrist may be recommended if improvements are not seen; further evaluation is sometimes required.
ADHD TREATMENT — The treatment of attention deficit hyperactivity disorder is discussed separately. (See "Patient education: Treatment of attention deficit hyperactivity disorder in children (Beyond the Basics)".)
WHERE TO GET MORE INFORMATION — Your child's health care provider is the best source of information for questions and concerns related to your child's medical problem.
This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients and caregivers, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient education: Attention deficit hyperactivity disorder (ADHD) in children (The Basics)
Patient education: Learning disabilities (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient education: Treatment of attention deficit hyperactivity disorder in children (Beyond the Basics)
Patient education: Depression in children and adolescents (Beyond the Basics)
Patient education: Bipolar disorder (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Attention deficit hyperactivity disorder in children and adolescents: Clinical features and diagnosis
Pharmacology of drugs used to treat attention deficit hyperactivity disorder in children and adolescents
Cardiac evaluation of patients receiving pharmacotherapy for attention deficit hyperactivity disorder
Long-term neurodevelopmental impairment in infants born preterm: Epidemiology and risk factors
Attention deficit hyperactivity disorder in children and adolescents: Overview of treatment and prognosis
Specific learning disabilities in children: Clinical features
Specific learning disabilities in children: Evaluation
The following organizations also provide reliable health information:
●Children and Adults with Attention Deficit Hyperactivity Disorder
●National Alliance for the Mentally Ill
●National Attention Deficit Disorder Association
●National Institute of Mental Health
(www.nimh.nih.gov/health/publications/adhd-listing)
●The United States Department of Education
(www2.ed.gov/about/offices/list/osers/index.html)
●The American Academy of Child and Adolescent Psychiatry
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