Normal Toddler Behavior vs ADHD

An official diagnosis of ADHD can be hard to pinpoint as its symptoms can often be indicative of other conditions, but it is especially hard to diagnose in children under the age of four, as most children naturally experience about a year of extreme energy that generally encompasses their third birthday. This realization may be, in turn, both comforting and exhausting as parents learn that their toddler is likely just exhibiting the rampant energy normal for their age group.

What is ADHD?

Children with an official diagnosis of ADHD consistently present symptoms of inattentiveness, over-activity, impulsivity, or some combination of these traits. In brain scans, it is possible to see the difference in brain chemistry in those diagnosed with ADHD, as their neurotransmitters behave differently from those without it. 

While we still don’t know exactly what causes ADHD, there is often thought to be a genetic predisposition, although environment can play a role as well. Other factors, such as diet, chemicals, and nutrition also contribute to the likelihood that a child will develop ADHD.   

Is This ADHD or Normal Toddler Beahvior?

Rates of ADHD diagnosis in some educational and medical settings are 300% higher than others. At least in part, this means that some communities are more overzealous to hand out an ADHD diagnosis than others. If you wonder if your child has ADHD, or if someone has recommended testing, ask that the AAP guidelines are followed.

AAP Guidelines for ADHD Diagnosis

Unfortunately, it’s all too often that “difficult” children are incorrectly labeled with ADHD. At the same time, quite a few children who would benefit from treatment remain undiagnosed. In both cases, related learning disabilities or mood disorders often go unchecked. Official AAP diagnosis is based on very specific symptoms with a strict set of criteria that must be met, including the fact that symptoms present themselves in a variety of settings, such as at home and at school. In fact, the newest set of clinical practice guidelines on ADHD recommends that children undergoing ADHD screening should also be screened for comorbid conditions with similar symptoms, including conduct disorder, oppositional defiant disorder, mood disorders/depression, anxiety, sleep disorders and learning disabilities. A 2016 parent survey found that 6 in 10 children with ADHD had a comorbid diagnosis (most commonly anxiety or other behavioral condition). 

Understanding Criteria for ADHD Diagnosis

It can be helpful to think of toddler energy like a bell curve, the same way we would see an array of different heights across a chart. Some people are shorter, some are taller, and most average somewhere near the middle. The same is true of children as they go through different phases of growth, fueled by what seems like the energy of a thousand suns. Their average energy levels will vary across a chart, but in that one year of extreme energy around age 3, even children without ADHD will exhibit the characteristics that fall into the official definition of an ADHD diagnosis. This is why it’s generally advised to wait until after a child’s fourth birthday before running tests of any kind. And it is very important to evaluate the child in multiple different environments before a diagnosis is made. 

The DSMV (Diagnostic and Statistical Manual of Mental Disorders, 5th edition) is the most common and useful criteria for diagnosing ADHD in children, as it differentiates symptoms into two categories: inattention and hyperactivity-impulsivity. In general, children with ADHD show a persistent pattern of these behaviors across multiple environments. 

An ADHD diagnosis should meet A-E of the criteria below: 

  1. Either 1 or 2:
  2. Six or more of the following symptoms of inattention have persisted for at least six months to a degree that is disruptive and inappropriate with developmental level:
  • a. Often fails to give close attention to details or makes careless mistakes in schoolwork, work, or other activities
  • b. Often has difficulty sustaining attention in tasks or play activities
  • c. Often does not seem to listen when spoken to directly
  • d. Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions)
  • e. Often has difficulty organizing tasks and activities
  • f. Often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort (such as homework)
  • g. Often loses things necessary for tasks or activities (toys, school assignments, pencils, books, or tools)
  • h. Is often easily distracted by extraneous stimuli
  • i. Is often forgetful in daily activities
  1. Six or more of the following symptoms of hyperactivity-impulsivity have persisted for at least six months to a degree that is disruptive and inappropriate with developmental level:


  • a. Often fidgets with hands or feet or squirms in seat
  • b. Often leaves seat in classroom or in other situations in which remaining seated is expected
  • c. Often runs about or climbs excessively in situations in which it is inappropriate (in adolescents or adults, may be limited to subjective feelings of restlessness)
  • d. Often has difficulty playing or engaging in leisure activities quietly
  • e. Is often “on the go” or often acts as if “driven by a motor”
  • f. Often talks excessively


  • g. Often blurts out answers before questions have been completed
  • h. Often has difficulty awaiting turn
  • i. Often interrupts or intrudes on others (such as butting into conversations or games)
  1. Some hyperactive, impulsive, or inattentive symptoms that caused impairment were present before age 12 years.
  2. Some impairment from the symptoms is present in two or more settings (such as in school or work and at home).
  3. There must be clear evidence of clinically significant impairment in social, academic, or occupational functioning.
  4. The symptoms do not occur exclusively during the course of a pervasive developmental disorder, schizophrenia, or another psychotic disorder and are not better accounted for by another mental disorder (such as a mood, anxiety, dissociative, or personality disorder).

Children meet the criteria for “ADHD, Predominantly Inattentive Type” when they have met inattention criteria (section A1) for the past 6 months. They meet criteria for “ADHD, Predominantly Hyperactive-Impulsive Type” when they have met hyperactive-impulsive criteria (section A2) for the past 6 months. When a child meets criteria for both section A1 and A2 for the past six months, he/she meets the criteria for “ADHD, Combined Type.” Now, parents who have tried to take a 3-year-old out for a leisurely dinner in a quiet restaurant (especially with other adults whose opinions they value) can quickly learn that typically developing children at this age can exhibit all of these behaviors.

It is important to keep in mind that there is no reliable way to diagnose ADHD in children under the age of 4. 

Different children go through energetic stages at different ages, and it can be helpful to check in with your child’s teachers or daycare to see how your child’s behavior compares to other children of a similar age. . 

 In early preschoolers, I would be more concerned about problems of social interactions with peers than with a short attention span, more concerned with those for whom it is difficult to obtain a babysitter than with those who are always on the go, and more concerned with those who consistently disrupt other children’s play than with those who fail to listen. In most children, the toddler full-tilt exuberance usually gives way to the dawning self-control of a preschooler at about age four. 

For children younger than four with particularly disruptive behaviors, behavioral modifications in the home and preschool may be helpful in addressing these concerns. Regular visits and evaluations with a pediatrician who is well-versed in ADHD may be helpful in honing in on any concerning behaviors and best strategies to address them. This doctor can also guide further therapies for children who meet the criteria for a formal ADHD after age four.  

Symptoms of ADHD and Lack of Sleep

It may seem hard to believe, but human beings can survive longer without food than they can without sleep – twice as long, in fact! What this tells us is that sleep plays such a critical role in health that its importance should not be ignored. The surprising news is that partial, or low-level, sleep deprivation has a bigger effect on behavior than either the short or long-term complete sleep deprivation, and that persistent, low-level lack of sleep can end up looking a lot like ADHD symptoms

Kids are proven to have better rates of attention, better grades, more elevated mood, behavior, and quality of life with greater rest. In contrast, lack of sleep is a major contributor to illness and depression. 

One of the best ways to help kids (and adults) get more rest is to set a consistent, early bedtime, lower the lights and turn off screens an hour before bed. This helps induce the body’s flow of melatonin, which increases with darkness and helps us to feel more calm and relaxed, signaling that the time to rest is near. Replacing screentime with a warm bath and a bedtime story can do wonders for your child’s energy levels and overall behavior the next day. 

The other thing to keep an ear out for is snoring. Snoring can disrupt your child’s slumber, whether they are aware of it or not. In fact, we find that snoring is more than twice as common in children who are diagnosed with ADHD. It is unlikely that ADHD causes snoring, and yet children who snore have higher correlations of ADHD. We are therefore left to surmise that the disturbance to sleep is the common factor. 

Thoughts on ADHD Medication

A July 2010 survey led by Consumer Reports Health revealed that parents are fairly split on whether they’d give their child ADHD medication again in retrospect. 52% said they would, while 44% would have foregone medication. The remaining percentage were unsure. 41% claimed to be satisfied with the medication, with 32% expressing a concern over side effects. The study also covered other, non-medication related strategies that parents had found to be helpful, including changing to an ADHD-focused school, one on one instruction, hiring a tutor or specialist, providing structure and schedules, and a range of other options like special class seating arrangements and taking brain health supplements such as fish oil. 

For younger children, the American Academy of Pediatrics recommends starting with parent training in behavior management and behavioral classroom modifications before considering medications. At any age, medications are best combined with behavior management and therapy. For school-age children, a comprehensive behavioral and educational support plan developed with the input of teachers, school administrators, and counselors t(such as an individualized education plan or IEP) is crucial to success. 

There are two main classes of medications used to treat ADHD, most of which are FDA-approved starting at 6 years of age. The stimulant class of medications are those most often used and recognized as ADHD medications. Examples include Ritalin, Adderrall, and Concerta. They tend to work quickly, and up to 80% of children diagnosed with ADHD have fewer symptoms when taking one of these medications. The most common side effects of stimulant medications include decreased appetite, stomachache, sleep problems, and minor growth delay. However, many of these side effects can be mitigated by changing the dose or timing of the medication.

The non-stimulant class of ADHD medications include Strattera, Clonidine, and Guanfacine. These do not work as quickly as stimulants but may relieve ADHD symptoms for up to 24 hours. As with many medications, side effects will vary with each child, and it is important to work carefully with your pediatrician to monitor the dose, frequency, and any side effects of medications that your child may be taking. 

Treating ADHD Without Medication

It is perfectly possible (and indeed, worth trying first) to treat ADHD without the intervention of medications. It can be helpful to think of medications not as a way to “solve” ADHD, but to provide a window of reprieve while looking for alternative solutions. Nutrition, physical activity, sleep, a child’s peers, environment, and exposure to chemicals are but a handful of things that contribute to a child’s health and wellness.

Beyond this, the FDA has now approved the first non-medication treatment for ADHD. It uses a special (and fun) video game to train the brain to increase focus on important tasks despite distractions. This can be powerful whether or not the child also needs prescription medications.

An important key to managing ADHD is to set specific, measurable goals at home and at school. Then, when you try an intervention you can monitor progress, evaluate the treatment, and readjust the plan. If you do choose to use medication, supporting a child’s treatment with adjustments in the areas listed above can still do a great deal to help a child’s progress.

Birth Month Correlation

It may come as a surprise, but a study published by the New England Journal of Medicine in 2018 showed that in districts where there was a September 1st cut-off date for kindergarten, those children born in August were more likely to be diagnosed with ADHD. These younger children may be classified as ADHD due to typical age-related behaviors which may seem abnormal when compared to their older peers in the classroom. This drives home the importance of using established medical criteria for an official diagnosis rather than purely observations or peer comparisons. 

For all children diagnosed with ADHD, and especially for those in the younger half of the class, it’s worth considering whether behavioral, sleep, exercise, or dietary approaches to improving focus and behavior may solve the problem – before resorting to prescription medications.

Disruptive Behavior

A variety of so-called “disruptive” behaviors are normal when a child is very young; it takes time and a certain level of awareness for children to begin to understand which actions are appropriate in a given setting, and a lot of it is dependent upon their ability to communicate. Consider a wailing baby who is simply trying their best to convey a need, versus a five-year-old calmly asking for a snack because they are hungry. 

It is a combination of maturity, awareness and ability to communicate that often contributes to how a child behaves, and whether or not their behavior is appropriate. Children with high energy levels, who seek attention, or who become bored easily are at a higher risk of ADHD diagnosis, even when this may not be the correct assessment. 

With kids who are disruptive (constantly seeking attention from adults or inserting themselves in other children’s conversations, for example), working on empathy can be very helpful–not telling them what to do, but helping them learn to identify what others are feeling, which can then lead to changes in behavior. Teaching empathy is a fantastic tool as children are naturally curious, and helping them to explore what they think others are feeling helps them to be more thoughtful in their actions. This is not just a tool to help in the short term, either. Children who grow up to be empathetic adults will also benefit from kinder, deeper relationships with one another. 

Do They or Don’t They?

Parents who struggle to keep up with a hyperactive 3-year-old may reach the point where they simply want answers. Unfortunately, a clear answer on an ADHD diagnosis will not really become clear until the child is at least age 4 or older. Remember, it’s normal (albeit hair-raising at times) for toddlers to have extreme energy. It’s a regular part of the growth process. 

If it turns out your child does have ADHD, finding specialists who work with behavioral and environmental modifications can be extremely helpful before deciding to resort to medication. It is possible to treat ADHD without drugs, and could end up sparing your child a host of possible side effects. If medication ends up being the best choice for your child, keep in mind there are several options, with combination therapy sometimes being the most beneficial. 

It may also be helpful to join a support group for parents of children with ADHD. Whatever your child’s diagnosis, taking time to find the right combination of treatments for their specific needs will go a long way in helping them feel better understood, and aid in regulating symptoms over time. 

References and Resources

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 5th edition. Arlington, VA., American Psychiatric Association, 2013.

Arnold LE, et al. Zinc for attention-deficit/hyperactivity disorder: placebo-controlled double-blind pilot trial alone and combined with amphetamine. J Child Adolesc Psychopharmacol. 2011;21(1):1-19. 

Centers for Disease Control and Prevention: ADHD

Danielson ML, et al. Prevalence of parent-reported ADHD diagnosis and associated treatment among U.S. children and adolescents, 2016. Journal of Clinical Child and Adolescent Psychology. 2018;47(2):199-212.

Derbyshire E. Do Omega-3/6 Fatty Acids Have a Therapeutic Role in Children and Young People with ADHD?. J Lipids. 2017;2017:6285218.

Layton, Timothy, et al. Attention Deficit Hyperactivity Disorder and Month of School Enrollment. New England Journal of Medicine. 2018; 379:2122-2130.

Millichap Gordon, et al. The Diet Factor in Attention Deficit/Hyperactivity Disorder. Pediatrics. 2012:129(2):330-337. 

Sinn N, Bryan J. Effect of supplementation with polyunsaturated fatty acids and micronutrients on learning and behavior problems associated with child ADHD. J Dev Behav Pediatr. 2007;28(2):82-91.

Wolraich ML, et al; Subcommittee on Children and Adolescents with Attention-Deficit/Hyperactive Disorder. Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents. Pediatrics. 2019;144(4):e20192528.

Dr. Greene is a practicing physician, author, national and international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.

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