What Is ADHD?

Attention deficit hyperactivity disorder

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ADHD (attention deficit hyperactivity disorder) is among the most common neurodevelopmental disorders of childhood. It affects around 11% of school-aged children, according to the national non-profit organization, CHADD (Children and Adults with Attention Deficit Disorder).

There are three types of ADHD:

  • Predominantly inattentive presentation
  • Predominantly hyperactive-impulse presentation
  • Combined presentation

As a neurodevelopmental disorder, ADHD arises from dysfunction in the brain and neurological system.

ADHD Signs and Symptoms in Children

Laura Porter / Verywell

Adults also can be diagnosed with ADHD, usually as a result of childhood ADHD that continues into adulthood. Around two-thirds of children with ADHD continue to experience symptoms as an adult. 

ADHD Signs and Symptoms

Children with ADHD have considerably more trouble than others sitting still, focusing, and paying attention—often to the degree they have trouble getting along with other children and learning in school. Similarly, AHDH that persists into adulthood can interfere with relationships and work performance.

Symptoms of attention deficit hyperactivity disorder depend on the type, but, in general, children with ADHD exhibit:

  • Frequent forgetfulness
  • Daydreaming and the appearance of not listening
  • Trouble staying on task
  • Disorganization
  • Avoidance of tasks that require mental focus
  • Forgetfulness—for example, does not follow through with homework or other tasks
  • Trouble sitting still, fidgeting, and squirming
  • Incessant talking
  • Risky behavior
  • Carelessness (lack of attention to details)
  • A pattern of making mistakes often
  • Trouble getting along with other kids (for example, unwilling to share or take turns)

In adults, ADHD symptoms can cause problems at work, at home, and with relationships with family members, friends, and co-workers. The hyperactivity of childhood may evolve into restlessness. What's more, the typical stresses of adulthood can worsen ADHD symptoms.


What causes ADHD is not well understood, although there is research to suggest genetics likely plays an important role. Other factors that may be linked to a high risk of having ADHD include:

  • Brain injury
  • Environmental conditions during fetal development or in early life, such as exposure to lead
  • Maternal use of alcohol or tobacco use during pregnancy
  • Premature delivery or low birth weight

There are also a number of myths about the potential causes of ADHD that have been debunked due to lack of scientific evidence: eating large amounts of sugar, watching too much television, and poverty or turmoil in the family. Such factors may, however, exacerbate symptoms of ADHD.


ADHD is diagnosed based on symptoms and an interview with a mental health professional such as a psychologist, psychiatrist, neurologist, or a primary care provider—often a pediatrician.

In the case of a child, the American Academy of Pediatrics recommends the diagnostic practitioner interview parents, teachers, and other adults who provide care for the child in order to consider their behavior in different environments and situations. The child may also may be interviewed, depending on their age.

Ultimately, a diagnosis of ADHD will depend on whether specific criteria listed in the 5th version of the Diagnostic and Statistical Manual (DSM-5) are met.

The DSM-5 is a manual for the assessment and diagnosis of mental disorders that is used by most diagnosticians to evaluate a person and see if there are signs and symptoms of a mental health disorder. According to the CDC, the DSM-5 says that a person with ADHD must show an ongoing pattern of inattention and/or hyperactivity-impulsivity and these symptoms must interfere with the person’s functioning or development. 

These criteria differ based on type of ADHD, but regardless, for a diagnosis of any type of ADHD to be made, the person being evaluated must have:

  • Exhibited severe hyperactive-impulsive or inattentive symptoms before age 12
  • Had several symptoms present in at least two (or more) settings (such as school and home, with peers, with relatives, or a caregiver)
  • Demonstrated that the symptoms interfere with the quality of functioning in a social, school or work settin
  • Had a formal evaluation, ruling out other primary underlying causes of the symptoms (such as a mood disorder, a personality disorder or anxiety disorder) 


There are three different types of ADHD as defined by the DSM-5. The type of ADHD a person has depends on the type of symptoms exhibited the most. The types of ADHD include:

Predominantly Inattentive Presentation: A child must have at least six of the following symptoms; an adolescent or adult must have five:

  • Trouble paying attention while performing tasks or engaging in play activities
  • Makes careless mistakes frequently
  • Frequently forgetting the details of daily tasks
  • Often easily distracted
  • Trouble finishing tasks
  • Often appears not to be listening when talked to directly
  • Frequently forgetful in performing daily tasks
  • Fails to finish homework or other tasks (problems following through, often gets sidetracked)

Predominantly Hyperactive-Impulsive Presentation: A child up to age 16 must have six symptoms; older adolescents and adults must have five:

  • Often fidgeting, tapping hands or feet, squirming while seated
  • Often gets up or leaves when expected to stay seated
  • Often runs or climbs inappropriately (adults may feel restless, but not engage in running or climbing)
  • Often unable to be involved in quiet leisure activities
  • Often talks non-stop
  • Often blurts out answers before the question has been completely asked in conversations
  • Unable to wait when taking turns
  • Often interrupts conversation when others are speaking

Combined Presentation: Has proportionately both types of symptoms (predominantly hyperactive-impulsive and predominantly inattentive).

Symptoms must be present for at least 6 months and they must be considered disruptive in either work, school, or social settings and inappropriate for the person’s developmental level. 

A person’s type of ADHD can change over time, as it’s common for to symptoms change as a child gets older. For example, a child with predominantly hyperactive-impulsive presentation ADHD may grow up to have predominantly inattentive presentation ADHD as an adult.

Differential Diagnosis

There are a number of conditions and disorders that may be mistaken for ADHD and so often have to be ruled out in order to make a definitive diagnosis, including:

ADHD Treatment

ADHD is treated with behavioral therapy, medication, or both. For preschoolers—children 4- and 5-year-olds—the first line of treatment is behavior-based, with parental involvement.

Behavioral Therapy

There are several behavioral treatment modalities recommended for ADHD, these include:

  • Behavior modification: Strategies aimed at increasing appropriate behaviors and decreasing inappropriate behaviors, based on the child’s symptoms.
  • Behavioral parent training: Training parents to respond in a way that will promote the child’s healthy growth and development and strengthen the parent and child relationship.
  • Social skills training: Provides a safe environment for a child to learn positive social skills, including how to interact well with other kids at school and with family members at home.
  • School interventions: Involves a trained professional who can work with the child’s teachers and school counselors to formulate a plan of action (called an IEP) aimed at implementing classroom interventions as necessary.
  • Organizational skills training: Aimed at teaching older kids organizational and time management skills at school and at home.


The two types of ADHD medications are available in short-acting, intermediate-acting, and long-acting forms:

  • Psychostimulants improve the ability to ignore distractions and focus thoughts. “They tend to reduce interruptive behavior, fidgeting, and other hyperactive symptoms,” according to researchers. The most commonly used psychostimulants are Ritalin (methylphenidate) and Adderall (dextroamphetamine). Studies show that stimulants improve ADHD symptoms in approximately 70% of adults and 70% to 80% of children.
  • Non-stimulant medicines may be used as stand-alone medications to treat ADHD or they may be prescribed in addition to other medications. Non-stimulant medications include Strattera (atomoxetine), Intuniv (guanfacine ), and Kapvay (clonidine). A 2009 study found that guanfacine improved working memory, lowered distractibility, and improved delayed gratification as well as behavioral flexibility in those with ADHD.

A combination of psychostimulants and non-stimulant medications is sometimes more effective than either type of drug alone. According to a 2016 study, guanfacine and d-methylphenidate was effective in improving behavioral and cognitive functioning for those who did not respond to stimulant drugs alone.

Most common side effects of medications for ADHD are mild; some subside after the medication has been taken for a while. If side effects are not short lived, the prescribing physician may lower the dosage or possibly prescribe a different drug. 

Side effects of ADHD medication include:

  • Insomnia (difficulty sleeping)
  • Loss of appetite
  • Weight loss
  • Nervousness or irritability
  • The most common side effects include:
  • Decreased appetite/weight loss
  • Social withdrawal

Less common side effects of stimulant medications may include:

  • Rebound effect (in which hyperactivity or moodiness increases as the medication wears off)
  • Tics (repetitive muscle movements such as eye blinking)
  • Minor delay in normal growth pattern

Alternative Treatments

There are many alternative and complimentary treatments that tout effectiveness for treating ADHD. However, the CDC warns many of these have been proven neither safe nor effective. This is not to say natural treatments for ADHD don't help at all—there simply is insufficient evidence they're effective.

Examples of alternative treatments for ADHD include:

  • Brain Gym
  • Luminosity
  • Cogmed: A program said to be effective in training the working memory in children with ADHD. 
  • Omega-3 supplements (fish oil supplements)
  • Massage therapy
  • Mindfulness training

Potentially Harmful ADHD Treatments

Before trying an alternative treatment for ADHD, talk to your healthcare provider. Some can interfere with prescribed treatment for ADHD and some can even be harmful, among them:

  • Allergy treatment
  • Megavitamins
  • Herbal supplements
  • Biofeedback
  • Restricted diets
  • Movement therapy
  • Anti-motion sickness treatment
  • Eye movement training


Living with a child or adolescent who has ADHD can be challenging for the entire family. As a parent, it’s important to learn about ways of helping your child overcome the challenges of ADHD, while reaching out to get support and help for yourself when needed. 

There are methods of helping manage your child's behavior and dealing with common ADHD challenges. You can learn more about ADHD Parenting Tips on helpguide.org. Getting professional help and education for parents and behavioral treatment for children (as early on in the disease process as possible) is imperative for helping parents and children with ADHD to effectively cope.

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12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. CHADD. About ADHD-Overview.

  2. America's Children and the Environment. Neurodevelopmental disorders.

  3. Canadian Mental Health Association. Attention-Deficit/Hyperactivity Disorder in Adults.

  4. Centers for Disease Control and Prevention. (CDC). Symptoms and diagnosis of ADHD.

  5. Schachar R. Genetics of attention deficit hyperactivity disorder (ADHD): recent updates and future prospects. Curr Dev Disord Rep. 2014;1(1):41-49. doi:10.1007/s40474-013-0004-0

  6. Centers for Disease Control and Prevention. What is ADHD?

  7. Wolraich ML, Hagan JF, Allan C, et al. Clinical practice guideline for the diagnosis, evaluation, and treatment of attention-deficit/hyperactivity disorder in children and adolescents. Pediatrics. 2019;144(4):e20192528. doi:10.1542/peds.2019-2528 

  8. Cleveland Clinic. Attention-Deficit/Hyperactivity Disorder (ADHD): Mangement and treatment.

  9. Advokat C, Scheithauer M. Attention-deficit hyperactivity disorder (ADHD) stimulant medications as cognitive enhancers. Front Neurosci. 2013;7. doi:10.3389/fnins.2013.00082

  10. CITE Yale School of Medicine. Guanfacine for the treatment of ADHD.

  11. Loo SK, Bilder RM, Cho AL, et al. Effects of d-methylphenidate, guanfacine, and their combination on electroencephalogram resting state spectral power in attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry. 2016 Aug;55(8):674-682.e1. doi:10.1016/j.jaac.2016.04.020

  12. Healthy Children.org. Common ADHD medications & treatments for children.