As a mother of two young children, I’m often in the company of other parents who vent about their difficulties with their child with ADHD and all of the remedies they’re using to “cure” the disorder. They’ve made their own treatment plans based on Google searches of causes of ADHD. As a child psychologist who specializes in ADHD and behavior disorders, it pains me to watch these parents struggle to understand the disorder and why their most recent attempt to rid their child of this disorder was unsuccessful.
For strategies to successfully make change, they should address the cause. Here, I first discuss popular myths of ADHD causes (you must have heard them at some point!) and then end with a list of science-supported causes of ADHD.
- TV and Video Games Cause ADHD. Many believe that children who engage in too much screen time (TV, video games, etc.) develop ADHD. Some early studies showed a correlation between TV watching and ADHD, but many studies that tried to replicate these findings were not successful. Therefore, there is not enough research to support this claim. Keep in mind that correlation does not equal causation; just because two variables are related does not mean that one caused the other. What many studies do show is that children with ADHD tend to watch TV and play video games. It is more likely that screen time is a result of ADHD and not a cause. Because children with ADHD take a lot of parent time and energy, it’s more likely that parents encourage these children to engage in screen time because it’s very entertaining to the children and allows parents a break to tend to other responsibilities.
- Food Additives Cause ADHD. This is one that I hear a lot. Some initial studies showed a small relationship between food additives and ADHD symptoms, but follow-up studies did not replicate these findings. So, to date, the conclusion that can be drawn from research is that food additives are not a cause of ADHD.
- Sugar Causes ADHD. This is also a popular myth. The bulk of research to date shows that ADHD is not caused by sugar consumption. Interestingly, the research also demonstrated how parental expectations about sugar consumption is related to an increase in parents’ report of ADHD symptoms. In other words, if parents hold the belief that sugar causes ADHD, they are more likely to report an increase in ADHD symptoms following their child’s consumption of sugary foods and drinks when an observer would more than likely see no increase in ADHD symptoms. The science to date does not support this myth.
- Poor Parenting Causes ADHD. It is true that there are more parent-child conflicts when children have ADHD, but parenting strategies do not cause ADHD. Again, just because two variables occur together does not mean one causes the other. In this case, the conflict between parents and children with ADHD is a result of ADHD, not the cause.
- Deficits in Sensory Integration Cause ADHD. To date, there is no evidence that children having deficits in processing and integrating sensory information leads to ADHD. ADHD affects motor sections of the brain, but research has not shown disruptions in brain areas that integrate sensory information with motor information.
Causes of ADHD Confirmed by Science
So, that leaves us with the question: What does cause ADHD? In general, neurological disorders can result from many different causes. Picture a computer that won’t turn on. What could be possible causes? Well, maybe someone dropped it. Maybe it was submerged in water. Maybe it got rained on but was not submerged in water. Maybe someone smashed it with a hammer in a fit of rage. All of these insults to the computer can result in the computer not turning on. The brain is similar. There can be many different insults to the brain, and these insults can affect many different regions or even the same regions. And, to complicate matters, problems don’t have to arise from external sources but can be caused genetically. In fact, two-thirds of ADHD cases are caused by genetics, not the environment; only one-third of cases are acquired from insults to the brain. And, even if one has a genetic predisposition to having a disorder, it may not emerge unless the environment causes disruptions. Goodness, it makes complete sense, when you think about it, why understanding causes of ADHD are misunderstood. It’s a complex topic!
The following are scientifically-supported causes of ADHD:
- Genetics. It is well known that ADHD runs in families and that genes are a significant contributor to ADHD. According to Russell Barkley, world renowned expert in ADHD, “ADHD is one of the most genetically influenced psychiatric disorders known.”
- Insults to the brain prenatally. Examples include maternal smoking and drinking, premature birth (especially with brain bleeding), and total number of pregnancy complications.
- Insults to the brain postnatally. In this category, examples include head trauma, reduced oxygen to the brain, tumors in the frontal lobe, infections in the frontal lobe, lead poisoning when children ages between the ages of 0 and 3, and streptococcal bacterial infection.
So, what’s the take-home message here? If you have a child with ADHD, please don’t believe that your parenting style is the cause. And, if you’re wondering why restricting your child’s diet is not working consistently, it’s because it’s likely not the underlying cause. For this particular disorder, your efforts are best spent in helping your learn accommodation strategies. If your child broke his leg, would you expect them to run a marathon? Of course not. You’d get a wheelchair or crutches and find ramps so that your child can meet his goal (of getting to the next level of the building). ADHD should be treated the same way. Understand that ADHD is a neurobiological issue, not your child wilfully misbehaving at home, in school, and with peers. Talk to your pediatrician to rule out medical causes of the symptoms, and then contact a professional who specializes in ADHD to learn how you can modify your child’s environment so he or she can be successful.
(information adapted from Russell A. Barkley’s lecture Advances in Understanding the Etiologies of ADHD)