What Are the Causes of Childhood ADHD?

What Are the Causes of Childhood ADHD?

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Researchers don’t know exactly what causes ADHD in children, but they do know the risk factors. Here’s some intel that might clarify.

Finding out that your child has attention deficit hyperactivity disorder (ADHD) may bring up a whole bunch of feelings.

And chances are, as soon as you heard the news, thoughts, questions, and “what ifs” started to swirl in your head: “Did I do something wrong? How did this happen? Are they going to be OK?

Let’s start at the beginning.

Technically, we’re not totally sure any child is born with ADHD. So far, we just know that genetics play an important role, thanks to studies of twins and families.

Roughly 3 in 4 children with ADHD have a relative with the condition. In fact, some studies have found this hereditability to be 70 to 80%.

“Kids are born with the underlying mechanisms that cause ADHD,” explains psychologist Jessica Myszak, “but babies and young children would never be diagnosed with ADHD.”

In other words: A baby might be born predisposed to have ADHD, but that doesn’t mean they’ll develop it.

ADHD has been diagnosed in children and teens who have no family history of the condition, which suggests there’s more than one cause.

Some other causes include:

Exposure to environmental toxins

Research suggests that exposure to certain toxins, either in utero or at a young age, might lead to ADHD.

One of those toxins could be lead, which is found in a variety of places, including in the paint of homes built before 1978 and in gasoline. The heavy metal seems to be associated with inattention, hyperactivity, and impulsivity — all symptoms of ADHD.

Another toxin that could be linked to ADHD is a pesticide called organophosphate. It’s commonly sprayed on lawns and agricultural products.

Research has shown that it affects kids’ neurodevelopment, so some scientists think it could also be linked to ADHD.

Health during pregnancy

Several studies have found that if a fetus is exposed to tobacco and or alcohol, it can increase the risk that the baby will develop ADHD.

For example, a 2018 study found that children were at greater risk of having ADHD if their birthing parent was a heavy smoker.

Another 2018 study made a connection that pregnant people who drank at least four alcoholic drinks in one sitting during pregnancy were more likely to have a child who had ADHD.

Poor nutrition and infections during pregnancy can raise the risk of the child having ADHD too.

“Known risk factors for ADHD include maternal diet during pregnancy,” Myszak says. “This also includes particular medications, such as antidepressants, antihypertensives, and caffeine.”

Being born early or having a low birth weight also appear to be risk factors.

Traumatic brain injury

Some ADHD diagnoses seem to be the result of brain damage, such as from:

  • a brain injury early in life
  • trauma
  • abnormal brain development


Some studies have also found that meningitis or encephalitis might also result in ADHD in kids.

“There is no single test to diagnose ADHD,” explains Dr. Dilip Karnik, a pediatric neurologist who specializes in ADHD and autism. “Some of the signs can also look like other disorders.”

That’s why ADHD diagnosis often involves evaluations by pediatricians and psychologists over a period of time, as well as parent checklists, in-office assessments, and teacher interviews.

The earlier it’s diagnosed, the better. That’s why, Karnik says, he “always encourages parents to trust their instincts.”

He continues, “Many parents often have a ‘gut feeling’ that their child is having difficulty, that something is not right, and if that’s the case, they should ask questions.”

Teachers often play a valuable role in noticing these common signs.

In preschool

Preschool is still a little too young to diagnose ADHD in most cases, unless the ADHD is severe.

“In general, children suspected of ADHD at this age are extremely impulsive and hyperactive,” Karnik says. “Much more than you would expect at 3 years old, and it’s not just an immaturity issue.”

Instead, doctors don’t usually diagnose ADHD in children until they’re at least 5 years old.

In elementary school

Elementary school is when most diagnoses happen.

“ADHD is easier to identify in a structured environment,” Karnik explains. So, teachers are more likely to notice the child who is constantly daydreaming, super talkative in class, or easily distracted during activities like circle time.

During parent-teacher conferences, you might hear that your kid has often been impulsive, demanding, or unable to complete projects.

However, says Myszak, your child shouldn’t just be having trouble at school. You should be seeing these same symptoms at home or in extracurricular activities too.

“If there is only one place that is problematic, it might be an issue with that particular environment rather than ADHD,” she says.

In middle and high school

“Sometimes kids are not identified [with ADHD] until much later,” Myszak says. “In these cases, there is evidence that the child had difficulty with attention, but either they were able to compensate for these difficulties when the material was easier, or due to cultural factors, their symptoms are not recognized.”

However, later in school, ADHD can have a bigger impact on schooling. Kids with undiagnosed and untreated ADHD can do poorly in school or get involved in high-consequence behavior, such as substance use.

There’s not much you can do to prevent ADHD — at least not yet.

The best thing you can do, says Myszak, is manage your wellness and take care with the environment you’re exposed to during pregnancy, as much as is feasible.

Myszak encourages parents to “receive prenatal healthcare and avoid exposure to drugs, alcohol, tobacco.”

The more you know about and understand your child’s diagnosis, the better you can help them cope.

That’s why Myszak recommends parents read books about ADHD, such as:

  • “Smart but Scattered” by Peg Dawson and Richard Guare
  • “12 Principles for Raising a Child with ADHD” by Russell A. Barkley

Other educational and supportive resources include:

  • HelpGuide, an independent nonprofit focused on mental health
  • ADDitude, a website and magazine dedicated to ADHD
  • CHADD, the largest national support organization for ADHD that features a resource directory to find professional help
  • ADDA, an association that provides info and training resources, and promotes ADHD awareness

You can also look into Parent-Child Interaction Therapy, which Myszak recommends to families who are struggling to manage their child’s behavior at home.

“It’s a parent-coaching model of therapy that helps parents learn to support their child and consistently and effectively manage their behavior,” she says.

What is ADHD?

ADHD is one of the most common neurodevelopmental disorders of childhood. It is usually first diagnosed in childhood and often lasts into adulthood. Children with ADHD may have trouble paying attention, controlling impulsive behaviors (may act without thinking about what the result will be), or be overly active.

COVID-19: Information for parenting children with ADHD

Signs and Symptoms

It is normal for children to have trouble focusing and behaving at one time or another. However, children with ADHD do not just grow out of these behaviors. The symptoms continue, can be severe, and can cause difficulty at school, at home, or with friends.

  • daydream a lot
  • forget or lose things a lot
  • squirm or fidget
  • talk too much
  • make careless mistakes or take unnecessary risks
  • have a hard time resisting temptation
  • have trouble taking turns
  • have difficulty getting along with others


There are three different types of ADHD, depending on which types of symptoms are strongest in the individual:

  • Predominantly Inattentive Presentation: It is hard for the individual to organize or finish a task, to pay attention to details, or to follow instructions or conversations. The person is easily distracted or forgets details of daily routines.
  • Predominantly Hyperactive-Impulsive Presentation: The person fidgets and talks a lot. It is hard to sit still for long (e.g., for a meal or while doing homework). Smaller children may run, jump or climb constantly. The individual feels restless and has trouble with impulsivity. Someone who is impulsive may interrupt others a lot, grab things from people, or speak at inappropriate times. It is hard for the person to wait their turn or listen to directions. A person with impulsiveness may have more accidents and injuries than others.
  • Combined Presentation: Symptoms of the above two types are equally present in the person.

Because symptoms can change over time, the presentation may change over time as well.

american sign language interpreting icon Learn about symptoms of ADHD, how ADHD is diagnosed, and treatment recommendations including behavior therapy, medication, and school support.

Causes of ADHD

Scientists are studying cause(s) and risk factors in an effort to find better ways to manage and reduce the chances of a person having ADHD. The cause(s) and risk factors for ADHD are unknown, but current research shows that genetics plays an important role. Recent studies of twins link genes with ADHD. 1

In addition to genetics, scientists are studying other possible causes and risk factors including:

  • Brain injury
  • Exposure to environmental (e.g., lead) during pregnancy or at a young age
  • Alcohol and tobacco use during pregnancy
  • Premature delivery
  • Low birth weight

Research does not support the popularly held views that ADHD is caused by eating too much sugar, watching too much television, parenting, or social and environmental factors such as poverty or family chaos. Of course, many things, including these, might make symptoms worse, especially in certain people. But the evidence is not strong enough to conclude that they are the main causes of ADHD.


Deciding if a child has ADHD is a process with several steps. There is no single test to diagnose ADHD, and many other problems, like anxiety, depression, sleep problems, and certain types of learning disabilities, can have similar symptoms. One step of the process involves having a medical exam, including hearing and vision tests, to rule out other problems with symptoms like ADHD. Diagnosing ADHD usually includes a checklist for rating ADHD symptoms and taking a history of the child from parents, teachers, and sometimes, the child.


In most cases, ADHD is best treated with a combination of behavior therapy and medication. For preschool-aged children (4-5 years of age) with ADHD, behavior therapy, particularly training for parents, is recommended as the first line of treatment before medication is tried. What works best can depend on the child and family. Good treatment plans will include close monitoring, follow-ups, and making changes, if needed, along the way.

Managing Symptoms: Staying Healthy

Being healthy is important for all children and can be especially important for children with ADHD. In addition to behavioral therapy and medication, having a healthy lifestyle can make it easier for your child to deal with ADHD symptoms. Here are some healthy behaviors that may help:

  • Developing healthy eating habits such as eating plenty of fruits, vegetables, and whole grains and choosing lean protein sources
  • Participating in daily physical activity based on age from TVs, computers, phones, and other electronics
  • Getting the recommended amount of sleep each night based on age

Get Help!

If you or your doctor has concerns about ADHD, you can take your child to a specialist such as a child psychologist, child psychiatrist, or developmental pediatrician, or you can contact your local early intervention agency (for children under 3) or public school (for children 3 and older).

The Centers for Disease Control and Prevention (CDC) funds the National Resource Center on ADHD external icon , a program of CHADD &ndash Children and Adults with Attention-Deficit/Hyperactivity Disorder. Their website has links to information for people with ADHD and their families. The National Resource Center operates a call center (1-866-200-8098) with trained staff to answer questions about ADHD.

For more information on services for children with special needs, visit the Center for Parent Information and Resources. external icon To find the Parent Center near you, you can visit this website. external icon

ADHD in Adults

ADHD can last into adulthood. Some adults have ADHD but have never been diagnosed. The symptoms can cause difficulty at work, at home, or with relationships. Symptoms may look different at older ages, for example, hyperactivity may appear as extreme restlessness. Symptoms can become more severe when the demands of adulthood increase. For more information about diagnosis and treatment throughout the lifespan, please visit the websites of the National Resource Center on ADHD external icon and the National Institutes of Mental Health external icon .

ADHD in Young Children

Attention-deficit/hyperactivity disorder (ADHD) is a biological disorder that causes hyperactivity, impulsiveness, and attention problems. Parents do not cause ADHD, but parents can play a key role in treatment. Behavior therapy is an effective treatment that improves ADHD symptoms without the side effects of medicine. It is an important first step for young children with ADHD and most effective when delivered by parents. With the support of healthcare providers and therapists, parents can learn specific ways to improve their child&rsquos behavior and keep their relationships strong. Clinical guidelines for ADHD treatment recommend that healthcare providers first refer parents of young children for training in behavior therapy before prescribing ADHD medicine. However, more young children are taking medicine for ADHD than receiving psychological services, which may include behavior therapy. Most families will benefit from behavior therapy and there are instances where medicine may be appropriate. Healthcare providers and families can work together to make sure children with ADHD are receiving the most appropriate treatment.

Healthcare providers can:

  • Follow the clinical guidelines for diagnosis and treatment of ADHD in young children. external icon , external icon
  • Discuss with parents the benefits of behavior therapy and why they should consider getting training.
  • Identify parent training providers in their area and refer parents of young children with ADHD for training in behavior therapy before prescribing medicine.

About 2 million of the more than 6 million children with ADHD were diagnosed as young children aged 2-5 years.

About 75% of young children with ADHD received medicine as treatment.

Only about 50% of young children with ADHD in Medicaid and 40% with employer-sponsored insurance got psychological services, which may have included behavior therapy, the recommended first-line treatment.

What to know about environmental causes of ADHD

Some environmental factors contribute to attention deficit hyperactivity disorder (ADHD), such as childhood stroke and brain injuries. However, genetics is the likely cause in most people.

ADHD is one of the most common mental health conditions doctors diagnose in children. It can be a lifelong condition, though symptoms may present differently in adulthood. Research suggests people tend to be born with ADHD rather than developing it spontaneously.

This article will discuss which environmental factors could be responsible for ADHD and whether a person can avoid or overcome them.

Share on Pinterest Photo editing by Lauren Azor MoMo Productions/Getty Images

Sometimes people think eating too much sugar, watching too much television, or a person’s socioeconomic environment causes ADHD. This is false. None of these factors result in a person developing ADHD.

However, researchers are looking into environmental factors that may be risk factors for ADHD in some people.

  • consuming alcohol or tobacco while pregnant
  • premature birth
  • low birth weight
  • exposure to lead (either during pregnancy or at a young age)
  • brain injury

Although the following environmental factors do not cause ADHD, they may influence the severity of symptoms.

Psychosocial factors

Some psychosocial factors may cause a person to develop ADHD-related health conditions, such as anxiety or mood disorders. Or they may increase the severity of a person’s symptoms.

Psychosocial factors that could increase the severity of ADHD include :

  • maternal depression
  • a disordered household environment
  • unsupportive parents or primary caregivers
  • poverty

Research is still ongoing to determine exactly how psychosocial factors affect ADHD symptoms.

However, it is important to note that these factors may not have a permanent effect on a person with ADHD.

Other environmental factors

Sometimes the amount of sleep a person has and the activities they do during the day can help alleviate some ADHD symptoms.

A 2017 prospective study found that when children slept for at least 10 hours a day, and participated in activities that stimulated their thinking, they had fewer ADHD symptoms.

Meanwhile, the time they spent watching TV and the amount of physical activity they completed had no impact on ADHD symptoms.

However, some of these findings conflict with evidence that suggests watching too much television and not exercising enough makes ADHD symptoms worse. Therefore, more studies are necessary to support these findings.

Although ADHD is a biological condition, managing environmental stressors could decrease the severity of symptoms.

Parents of children with ADHD should take care to minimize children’s exposure to family conflict, even when their child’s symptoms make parenting a challenge. Family conflict creates stress that could contribute to a child experiencing antisocial behavior symptoms as well as ADHD.

  • creating routines
  • managing distractions, such as the television
  • limiting choices to avoid overwhelming the child
  • creating a positive environment
  • promoting healthy food choices
  • encouraging physical exercise

Diagnosing ADHD is difficult and requires several tests.

ADHD shares a lot of similar symptoms with conditions that disrupt a person’s sleep or mood. For that reason, some people may receive a diagnosis of these conditions first, before ADHD.

To receive an ADHD diagnosis, a person must meet certain criteria from the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5).

Due to the nature of ADHD, a person must have six or more symptoms of inattention and hyperactivity if they are 16 years old, or five or more if they are 17 years old or an adult. They must also have these symptoms for at least 6 months.

  • making careless mistakes
  • not holding attention
  • failing to complete homework or other duties
  • avoiding tasks that require mental effort for a long period
  • losing things
  • becoming easily distracted
  • being generally forgetful during daily activities

Hyperactivity symptoms include:

  • fidgeting or tapping hands and feet
  • getting up often when sitting down
  • leaving situations unexpectedly
  • not playing quietly
  • always on the go
  • talking excessively
  • blurting out answers before a person has finished the question
  • trouble waiting
  • interrupting

If someone thinks they or their child has ADHD, they should get in touch with their doctor, who can arrange testing.

Focus Topic : Two children referred for problems with noncompliance and hyperactivity

Case 1 – Michael

Michael, a 4-year-old boy, was referred to a child psychologist to be evaluated for ADHD. His parents reported that Michael would not comply with their instructions. They also complained that Michael would not remain seated during “quality time” with his father. The evaluating psychologist interviewed the family, and by all accounts Michael was noncompliant and often left his seat. Specifically, when Michael’s mother asked him to prepare his preschool lunch, Michael would leave the kitchen and play with his toys soon after opening his lunch box. Further, the psychologist found that quality time involved Michael and his father sitting down for several hours to watch movies. In other settings, such as preschool, Michael was compliant with his teacher’s request and no more active than his peers.

In this case, Michael’s parents held unrealistic expectations for a child at Michael’s developmental level. The psychologist would likely educate Michael’s parents about normative child development rather than diagnosing Michael with ADHD.

Case 2 – Jake

Jake, a 10-year-old boy, was referred to the same psychologist as Michael. Jake’s mother was concerned because Jake was not getting ready for school on time. Jake also had trouble remaining seated during dinner, which interrupted mealtime for the rest of the family. The psychologist found that in the morning, Jake would complete one or two steps of his routine before he became distracted and switched activities, despite his mother’s constant reminders. During dinnertime, Jake would leave his seat between 10 and 15 times over the course of the meal. Jake’s teachers were worried because Jake was only able to complete 50% of his homework. Further, his classmates would not pick Jake for team sports during recess because he often became distracted and wondered off during the game.

In this case, Jake’s symptoms would not be considered developmentally appropriate for a 10-year-old child. Further, his symptoms caused him to experience impairment at home and school. Unlike Michael, Jake probably would be diagnosed with ADHD.

Why Do Some Children Develop Behavior Disorders?

The reasons that some children develop ADHD are complex, and it is generally recognized that a single cause is insufficient to explain why an individual child does or does not have the disorder. Researchers have attempted to identify risk factors that predispose a child to develop ADHD. These risk factors range in scope from genetic (e.g., specific gene polymorphisms) to familial (e.g., poor parenting) to cultural (e.g., low socioeconomic status). This section will identify some of the risk factors that are thought to contribute to ADHD. It will conclude by reviewing some of the more controversial ideas about the causes of ADHD, such as poor parenting and children’s diets, and review some of the evidence pertaining to these causes.

Studies of twins have shown that genetics are primarily responsible for ADHD.

Although genetics appear to be a main cause of ADHD, recent studies have shown that environmental risk factors may cause a minority of ADHD cases. Many of these environmental risk factors increase the risk for ADHD by disrupting early development and compromising the integrity of the central nervous system. Environmental influences such as low birth weight, malnutrition, and maternal alcohol and nicotine use during pregnancy can increase the likelihood that a child will develop ADHD (Mick, Biederman, Faraone, Sayer, & Kleinman, 2002). Additionally, recent studies have shown that exposure to environmental toxins, such as lead and pesticides, early in a child’s life may also increase risk of developing ADHD (Nigg, 2006).

The Science behind attention Deficit Hyperactivity Disorder (ADHD)

Brain scientists that most common disorders such as anger-control problems, mood disorders, obsessive-compulsive disorders, and anxiety are a result of the deficiencies in specific neurotransmitters.

Attention deficit hyperactivity disorder was found to be the first one that developed as a result of the deficiency of these specific neurotransmitters. To correct this deficiency, norepinephrine the first disorder was found to respond to medication. All neurotransmitters, including the norepinephrine, are synthesized in the brain. Dopa is the basic building unit for norepinephrine. Dopa units are linked to form a dopamine molecule, which is then converted to form norepinephrine.

Dopamine, therefore, plays a role in ADHD. This is due to the fact that the chemical transmits signals between brain nerves and it’s linked to mood, sleep, learning, attention, and movement.

Listen to “Everything You Wanted to Know About ADHD Causes and Treatments” with Stephen Hinshaw, Ph.D.

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Stephen Hinshaw, Ph.D., explains the genetic, environmental, and psychosocial factors that lead to ADHD, and provides an overview of the best behavioral, medicinal, and natural treatments for children and adults.

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This ADHD Experts webinar was broadcast live on December 8, 2015

10 Theories About ADHD Causes

Some theories about ADHD causes have good evidence to support them and some don't. Find out what may cause ADHD and what probably doesn't.

Attention deficit hyperactivity disorder (ADHD) is now recognized as a common childhood disorder that can continue into adulthood. While diagnosing ADHD has become more common, understanding ADHD causes remains a work in progress. "There is no single test for diagnosing ADHD and there is no single ADHD cause," notes Loren R. Dribinsky, MD, a psychiatrist at the Lahey Clinic in Burlington, Mass.

Many theories about ADHD causes have been considered over the years, including:

  • Lack of good parenting
  • Stressful family situations
  • Excessive exposure to TV and video games
  • Lack of structure at school

Quite a few of these theories have been abandoned and new theories have replaced them. "One reason why we don't know all the ADHD causes is that we can study genes and brain changes, but it is very hard to study environmental triggers," explains Dr. Dribinsky.

Though we don’t completely understand why some children are more susceptible to ADHD than others, the brain changes that are seen in children with ADHD symptoms are not theoretical. Studies show that regions of the brain affected by ADHD are the same regions that control attention as well as impulse control in children without ADHD. Here are 10 theories — some more plausible than others — to explain the brain changes that cause ADHD symptoms:

  1. Genetics. ADHD symptoms tend to run in families. Studies show that one in four children with a diagnosis of ADHD will have a close family member with ADHD.
  2. Lead exposure. Studies have shown an association between lead exposure and ADHD symptoms in young children. Lead may enter a child's drinking water from old plumbing fixtures. Children may also be exposed from lead paint. "These exposures are known to increase the risk of ADHD, but these exposures are becoming increasingly rare and most children with a diagnosis of ADHD have no evidence of significant lead exposure," Hunter notes.
  3. Cigarettes and alcohol. Two toxins that have been shown to increase the risk of ADHD in children are cigarette smoke and alcohol. Smoking and drinking during pregnancy are associated with a number of serious health risks for both mother and fetus. Not surprisingly, several studies have specifically linked these substances to an increased risk of having a child with ADHD.
  4. Medications taken during pregnancy. A study done in the Netherlands found that children of women who were treated for high blood pressure during pregnancy with a medication called labetalol (Normodyne, Trandate) had a significantly higher risk of ADHD. "It may be that some medications given to a mother may interfere with fetal oxygen, but these are isolated findings and require more research," cautions Hunter.
  5. Fluoride. The theory that fluoride could cause ADHD arose from a study done in rats. Although rats exposed to fluoride during the study did develop ADHD symptoms, this may not necessarily translate into increased risk among humans. "I know of no convincing evidence that fluoride is a significant ADHD risk factor for children," says Dribinsky.
  6. Sugar and sugar substitutes. Both refined sugar and sugar substitutes have been studied as possible ADHD causes. Most studies show that neither sugar nor sugar substitutes affect children's behavior or their learning ability. According to the National Institute of Mental Health (NIMH), there is actually more research to suggest that sugar is not linked to ADHD symptoms than there is research to support an association between the two.
  7. Celiac disease and food allergies. Some research supports the theory that food intolerance or food allergies, such as in the intolerance to the protein gluten seen in celiac disease, may be a trigger for ADHD symptoms. Studies have shown that a small percentage of children may get some relief from ADHD symptoms with diet restrictions. "Food sensitivities and nutritional deficiencies may play a role, but more research needs to be done," says Dribinsky.
  8. Food additives. It has long been suspected that food additives such as food coloring or food preservatives might cause ADHD symptoms or make them worse. Recent research published in Britain supports a link between these additives and an increase in ADHD symptoms. Research is under way to see if these findings can be confirmed. "The effects of food additives are probably negligible for most children with ADHD, but some children may be more sensitive than others," Hunter explains.
  9. Pesticides. "Recent studies done at Harvard suggest that pesticide exposure may increase the risk of ADHD in children," notes Hunter. The researchers found that children who had high levels of pesticide in their urine had almost double the risk of ADHD as children who had undetectable levels.
  10. Complications during pregnancy. Many studies show that a difficult pregnancy can lead to ADHD. These may be complications that occur during fetal development in the womb, or complications that affect the baby's brain during delivery. Complications that have been identified include high blood pressure during pregnancy, bleeding before the birth of the baby, babies who remain in the womb beyond their due date, long delivery time, and anything that impacts the baby’s oxygen supply during birth.

It remains unclear which of these theories play the biggest role in ADHD symptoms. It’s likely that a number of factors work together to determine whether a child develops ADHD. As Dribinsky points out, "We know that children with ADHD have brains that function differently … What we need to know more about is how the environment triggers ADHD symptoms."

Adds Hunter: "Children who have a genetic predisposition for ADHD may be more vulnerable to pesticides, toxins, or other triggers. The areas of the brain that are responsible for attention and activity regulation are very sensitive."

While exact ADHD causes are not yet known, this is an exciting and active time for research and discovery in ADHD. Some earlier theories seem less promising now, but new theories may hold the key to unraveling the mystery of ADHD in the future.

What Doesn’t Cause ADHD

Although it’s been debated, research does not show that ADHD is caused by eating too much sugar or watching a lot of TV.

Other factors that have largely been ruled out as root causes of ADHD include:

  • Parenting styles. There are techniques that parents can use which help support a child who has ADHD, though.
  • Diet. A healthy diet is good for the brain, but no particular food or dietary pattern has been shown to cause ADHD.
  • Playing video games. There is no evidence that playing video games causes or worsens ADHD. At the same time, some kids with ADHD may be drawn to fast-paced games on the screen. Children with ADHD may “hyperfocus” while playing video games, which can lead to spending too much time playing video games. So while the games themselves don’t cause ADHD, they’re something that parents may need to limit, especially in children with ADHD.
  • Poverty
  • Stress or unstable

Clinical Implications

Childhood externalizing behavior problems are important predispositions to later violent offenders (Betz, 1995 Farrington & Hawkins, 1991). Violence prevention and protection from victimization have become two of the most pressing issues facing society today (Ahmad, 2004 Calabro, Mackey, & Williams, 2002 Comerci, 1996 Morrison et al., 2002 Stoff et al., 1997). Identification of early risk factors for childhood and adolescent externalizing behavior is a critically important step for developing successful prevention programs for adult violence. As one of many examples, Webster-Stratton & Hammond (1997) have demonstrated that parent training that results in more competent and positive parenting by the mother is associated with reduced conduct problems in the child. Consequently, studies on risk factors may help to further inform which early intervention and prevention programs may help prevent the development of externalizing behavior in children.

However, to date there has been little recognition of the ways in which the nursing profession can affect the prevention of externalizing behavior. A study by Olds et al. (1998), which demonstrated the effectiveness of pre-and postnatal home visitations by nurses in significantly reducing juvenile delinquency 15 years later, provides a new vista for nursing. From the health prevention and promotion perspective, using a biosocial approach to understanding childhood externalizing behavior, juvenile delinquency, and violence has turned into a new and perhaps inevitable endeavor for the nursing scientist, educator, and practitioner. Because externalizing behavior is a major predisposition to violence, tackling the causes of this behavior problem can help tackle violence.

For example, birth complications combined with poor parenting (Gardner, 2000 Hodgins, Kratzer, & McNeil, 2001), maternal rejection (Raine, Brennan, & Mednick, 1994), or social adversity (Arsenault, Tremblay, Boulerice, & Saucier, 2002) were found to directly predispose to externalizing and antisocial behavior problems. Therefore, intervention involving better prenatal care, or effective parenting or better social service, can help reduce the risk factors. Furthermore, birth complications also were found to be linked to poor cognitive ability (Fattal-Valevski et al., 1999 Taylor, Klein, Schatschneider, & Hack, 1998), and poor cognitive ability was found to predispose to externalizing behavior problems (Deitz, Lavigne, Atrend, & Rosenbaum, 1997 Huesmann, Eron, & Yarmel, 1987).

In addition, early poor cognitive ability was found to be linked to later externalizing behavior in children in other studies. Liu et al. (in press) have shown that, compared to controls, children with malnutrition at age 3 years have higher externalizing behavior problems (antisocial, aggressive, and hyperactive behavior) at ages 8, 11, and 17. Results were independent of psychosocial adversity, and low IQ mediated the link between malnutrition and externalizing behavior at ages 8 and 11 years.

If the mediation model illustrated in Figure 1 is correct, it would be expected that factors that improve intelligence would reduce antisocial behavior. Early enrichment programs such as Head Start, which improve cognitive ability (Barnett, 1998), may be effective in preventing antisocial behavior (Raine, Mellingen, Liu, Venables, & Mednick, 2003). Because malnutrition and birth complications were found to contribute to low intelligence (Liu, 2004 Liu, Raine, Venables, Dalais, & Mednick, 2003), it could be expected that interventions to reduce malnutrition and birth complications would be helpful in reducing outcome for poor cognitive ability, and hence outcome for externalizing behavior.