A diagnosis of attention deficit hyperactivity disorder (ADHD) usually happens during the elementary school years, but it can happen earlier, when the child is still a toddler. Signs of ADHD may not be clear in toddlers.

Children with ADHD often have trouble paying attention, and they may display hyperactive and impulsive behaviors. These features can affect the child’s relationships with family, friends, and teachers.

In the United States, there is concern that growing numbers of children are receiving this diagnosis and that some may be taking medication too early. Others argue, on the other hand, that an early diagnosis can lead to more effective treatment.

At what age does ADHD begin, and can infants and toddlers have symptoms? At this early stage, is there any way to treat ADHD?

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The Centers for Disease Control and Prevention (CDC) have reported that, as of 2016, around 6.1 million children ages 2–17 in the U.S. had received a diagnosis of ADHD. This figure included around 388,000 children aged 2–5 years.

Before 2011, the American Academy of Pediatrics (AAP) only had guidelines for diagnosing ADHD in children ages 6–12.

In 2011, they expanded their guidelines to include preschoolers and adolescents, widening the range to incorporate ages 4–18.

Some children receive a diagnosis before the age of 4. However, there are no clinical guidelines for diagnosis at this age.

It can be hard to notice symptoms of ADHD in children younger than 4 years of age. A short attention span, impulsivity, tantrums, and high levels of activity are common during certain stages of development. Many children go through the “terrible twos,” and not all have ADHD.

Children who are very active and have a lot of energy — but not ADHD — can usually focus when necessary for stories or to look through picture books. They are also able to put toys away or sit and do a puzzle, for example.

Children with ADHD are often unable to do these things. They may show extreme behavior that disrupts activities and relationships. For a diagnosis of ADHD, a child must display these behaviors for at least 6 months in more than one setting, such as at home and at nursery school.

Toddlers with ADHD may:

  • be restless
  • run around, climb, and jump on everything
  • be constantly “on the go,” as if they are “driven by a motor”
  • talk nonstop
  • be unable to concentrate or listen for long
  • find it hard to settle down, take naps, and sit for meals

However, some children with ADHD may focus well on things that interest them, such as particular toys.

If a parent or caregiver thinks that their toddler is displaying behavior that is excessive and intense, and if this behavior affects family life and occurs frequently, they should speak with their child’s doctor for an evaluation.

Guidelines for diagnosing ADHD do not cover children ages 3 years or younger.

However, there is evidence that doctors are diagnosing ADHD in toddlers.

Factors that may cause a doctor to suspect ADHD at this age include:

  • genetic factors
  • if the mother used drugs or alcohol during pregnancy
  • if the mother smoked during pregnancy
  • if the mother was exposed to environmental toxins during pregnancy
  • preterm birth or low birth weight
  • central nervous system problems at critical moments in development
  • a delay in motor development, speech, and language
  • behavioral difficulties
  • a family history of ADHD

The 2010–2011 National Survey of Children’s Health in the U.S. found that around 194,000 children ages 2–5 had received a diagnosed of ADHD during the year.

How do doctors diagnose ADHD?

In order to diagnose ADHD in an older child, a doctor may:

  • perform a medical examination
  • look at personal and family medical histories
  • consider school records
  • ask family, teachers, babysitters, and coaches to complete a questionnaire
  • compare symptoms and behavior to ADHD criteria and rating scales

To diagnose ADHD in older children and adults, a doctor will also observe and ask about characteristics, such as:

  • lack of attention to detail when performing tasks
  • difficulty staying focused on tasks
  • appearing not to listen when spoken to
  • not following instructions
  • difficulty organizing chores
  • often losing things and forgetting to do things
  • fidgeting and not being able to stay seated
  • running or climbing in inappropriate places
  • excessive talking
  • inability to do something quietly
  • difficulty waiting for their turn

What about diagnosing younger children?

For younger children, it may be difficult to know whether they would meet these criteria.

Sometimes, a problem with development, such as a language delay, may lead to a wrong diagnosis of ADHD.

Other medical conditions can cause similar symptoms, including:

  • a brain injury
  • learning or language problems
  • mood disorders, including depression and anxiety
  • other psychiatric or neurodevelopmental disorders
  • seizure disorders
  • sleep problems
  • thyroid problems
  • vision or hearing problems

Preschool-age children or infants who show symptoms of ADHD should see a specialist for an evaluation. A relevant specialist may be a speech pathologist, developmental pediatrician, psychologist, or psychiatrist. They can help a physician make an accurate diagnosis.

There are guidelines for treating ADHD in children ages 4 years and older, but there are currently no guidelines for treating ADHD in toddlers.

In children aged 4–5 years, a doctor might recommend:

Behavioral therapy: A parent or teacher could deliver this.

Medication: If symptoms do not improve with behavioral therapy, and especially if they are moderate to severe, a doctor may recommend methylphenidate hydrochloride (Ritalin) and other stimulant medicines.

The doctor will monitor the dosage and change it, if necessary, to ensure that the child experiences the maximum benefit and the fewest possible side effects.

It is important to note that the U.S. Food and Drug Administration (FDA) have not approved the use of this drug in children under 6 years old, due to a lack of evidence that it is safe or effective.

The FDA note that stimulant medications can have side effects, including slowing a child’s growth.

Early treatment for toddlers

The CDC recommend training for parents and behavior therapy for young children. As a first step, they say that behavior therapy:

  • teaches parents ways to manage their child’s behavior
  • appears to work as well as medication in young children
  • prevents the side effects that can occur with medication

The therapist will work with the child to help them learn:

  • new ways of behavior that do not cause problems
  • new ways of expressing themselves

When the child is old enough to attend kindergarten or school, the parents or caregiver should ask the school about the possibility of educational support.

In 2014, a CDC official presented a report, stating that over 10,000 toddlers aged 2–3 years may be receiving medication for ADHD in ways that do not meet the established guidelines in the U.S.

The mental health watchdog Citizens Commission on Human Rights has gathered data suggesting that the number of toddlers receiving treatment for ADHD and other mental health issues in the U.S. may be higher than this.

They say that in addition to the 10,000 toddlers receiving ADHD medication:

  • 318,997 are being administered antianxiety drugs
  • 46,102 are being given antidepressants
  • 3,760 are receiving antipsychotics

They also found that among babies aged 1 year or younger:

  • 249,669 are being given antianxiety medications
  • 24,406 are being administered antidepressants
  • 1,422 are receiving drugs for ADHD
  • 654 are taking antipsychotics

The figures above indicate that babies and toddlers may be overmedicated.

There are no guidelines for treating toddlers or babies with ADHD. However, guidelines for slightly older children suggest trying behavioral therapy before using medication.

In addition, one study reports that nearly 50 percent of toddler participants aged under 3 and receiving psychotropic medications were not monitored as often as every 3 months.

This suggests that toddlers and babies may be taking ADHD medications for up to 6 months at a time without doctors checking on the effects.

The AAP call on doctors to weigh the risks of administering ADHD medication to very young children against the potential harm of delaying diagnosis and treatment.

Experts disagree on whether the growing number of ADHD diagnoses among U.S. preschool children is helpful or harmful.

Some worry that doctors are overdiagnosing the condition and that children are receiving medications at far too young an age. On the other hand, an early diagnosis can mean that a child receives help more quickly.

It can be difficult to diagnose a child with ADHD before the age of 4–5 years, especially as there are no specific diagnostic criteria for toddlers and babies.

If parents or caregivers suspect that a child has ADHD, they should seek advice from a doctor.

The doctor will first rule out other conditions. If, after an evaluation, a doctor gives a toddler a diagnosis of ADHD, they will offer advice and support and inform the caregiver about behavioral therapy.

If the doctor suggests medication, some caregivers may wish to consider a second opinion before starting this treatment.

With appropriate treatment, it is possible to manage the symptoms of ADHD.