ADHD Causes: Is ADHD Genetic?

Do you have a family member with ADHD and wonder if you have it, too? Perhaps you’ve been diagnosed with ADHD and are concerned you may pass it down to your children.

Scientists have not yet been able to pinpoint the exact cause of ADHD. Current research suggests that a combination of factors, such as your genes and environment, may be responsible for the development of ADHD.

If you or someone you know is struggling with ADHD, take advantage of ADDA’s resources to find additional help and support.

Read on to discover more about the heritability of ADHD and other possible causes.

Is ADHD Genetic?

Yes, ADHD can run in families. The genes you inherit from your parents can significantly affect your risk of developing ADHD. Those with a parent, sibling, or close relative who has ADHD are more likely to have ADHD as well.^[1]

Available research shows that genes play one of the biggest roles in the development of ADHD.

For instance, scientists found that children with siblings that have ADHD are nine times more likely to have ADHD than those with non-ADHD siblings.^[2] Other research suggests that around 40% of parents with ADHD have children who also meet the criteria for an ADHD diagnosis. ^[3]

While ADHD shows a strong genetic link, this doesn’t automatically mean that your child will inherit ADHD. Other factors, such as a person’s environment, can also influence how likely they are to develop ADHD. This is backed up by studies of twins, in which a diagnosis of ADHD in one twin was not always present in the other.^[2]

Other Possible Causes of ADHD

While the answer to the question, “Is ADHD hereditary?” is a likely yes, genes aren’t the only factor involved in the development of ADHD.

The following are some other possible causes of ADHD.

Brain Function and Structure

The ADHD brain may differ from the non-ADHD brain in three different ways: Function, structure, and chemistry.

One such difference in brain function involves the regions of the brain collectively called the default mode network (DMN). This brain system takes care of mental processes like daydreaming, imagining the future, retrieving memories, and internal reflection.

The DMN is turned on when the brain isn’t actively engaging with a specific task, known as the “resting state.” And when it’s time to perform a task, the DMN should deactivate.

In people with ADHD, though, this part of the brain possibly never quiets down, making it harder to focus and pay attention to the task at hand.^[4]

The structural differences between the ADHD and non-ADHD brain may also explain the presence of various symptoms related to impulse control, attention, and emotional regulation.

Here’s what researchers have discovered about the structure of the ADHD brain:^[5]

• The overall brain size in children with ADHD tends to be smaller than in children without ADHD. ADHD brains may mature slower than non-ADHD brains.
• In those with ADHD, areas of the brain, such as the amygdala and hippocampus, may have a smaller volume, affecting how the person processes and regulates emotions.
• Other brain regions, including the frontal lobe, may also be smaller in volume, leading to inattention, impulsivity, and problems with social interactions.

Finally, a difference in the brain chemistry of the ADHD brain could be associated with a chemical messenger called dopamine.

A dysfunction in the dopamine pathways of the ADHD brain may change how the brain processes motivation and reward. This could explain why some adults with ADHD experience a lack of motivation.^[6]

Despite the many studies being conducted about the ADHD brain, scientists still don’t know exactly why these differences happen. As a result, there’s still a lack of explanation for what gives rise to the functional, structural, and chemical differences between an ADHD and a non-ADHD brain.

Culture’s Impact on ADHD Symptoms and Diagnoses

A newer and more controversial theory suggests that modern lifestyle and culture may be another piece of the puzzle.

Michael Ruff, M.D., Clinical Associate Professor of Pediatrics at Indiana University, mentions that a handful of ADHD cases, at the very least, may be driven by high-stress, fast-paced, and instant-gratification lifestyles.

He suggests that a world filled with ultra-fast-moving video games, smart devices, and a huge variety of TV shows may impact how a child’s brain matures.

For instance, some research found that the more TV a child watches, the higher their risk of developing attentional problems. Dr. Ruff notes that these findings may be suggestive of the impact of environmental factors on ADHD development.^[7]

Of course, the role of environmental influences does not invalidate the fact that ADHD is most significantly linked to genetic factors.

Pregnancy Problems and ADHD

Several pregnancy-related factors may impact the risk of ADHD development.

Children born prematurely or with a low birth weight may be at a higher risk of ADHD. This may be due to a lack of nutrients and oxygen during pregnancy, restricting the fetus’ growth and development.^[8]

Premature births may also be associated with changes in specific hormone levels and increased inflammation. This might contribute to the impaired maturation of the brain, behavioral problems, and the development of ADHD.^[8]

Other pregnancy-related factors that may increase the risk of ADHD development in the child include:^[9],[10]

• Experiencing regular or excessive stress while pregnant
• Experiencing physical health issues, diseases, or mental health conditions while pregnant
• Smoking or consuming alcohol during pregnancy
• Trauma to the abdomen that’s severe enough to require medical attention while pregnant

Pregnant women with high-risk children (children with at least one parent with ADHD) may require extra support, attention, and counseling to minimize the impact of modifiable pregnancy factors on their child’s risk of ADHD.

What Doesn’t Cause ADHD

There’s a lot of confusion and misperceptions surrounding the role of specific factors, such as diet or parenting, in ADHD development.

Based on research findings, the following are some factors unlikely to lead to ADHD, at least in most cases:

• How you were raised: There is currently no solid evidence that improper parenting techniques can cause the inattention, impulsivity, or hyperactivity associated with ADHD.
• Time spent playing console games: Research suggests that the amount of time spent playing video games is unlikely to cause ADHD or worsen the condition. However, children with ADHD may spend more time on video games without proper management due to their tendency to hyperfocus.^[11]
• Nutritional factors: There is no clear evidence that your diet and food choices can cause ADHD. Current studies about the impact of diet on ADHD symptoms are also conflicting. Dietary changes, such as eliminating “trigger” foods or incorporating more vitamins and healthy fats, have not yielded significant benefits in people with ADHD.^[12]
• Instability or stress: Stress may not directly cause ADHD, but research demonstrates that stress can worsen ADHD symptoms. Higher exposure to stressful events during childhood can also increase the risk of symptoms persisting into adulthood.^[13]
• Lack of financial resources: Poverty and a lower social economic status might not be a direct cause of ADHD. However, a lack of financial resources can make it more difficult to attain proper ADHD treatment and medical advice.

What To Do When You Have a Family History of ADHD

ADHD has a strong genetic component, but this does not necessarily mean your child will inherit ADHD.

The best thing you can do is to stay observant and vigilant of potential symptoms your child may display. Detecting them early on allows your doctor to recommend therapy sooner to help your child effectively manage their symptoms.

Alternatively, if a close relative has been diagnosed with ADHD, you may wonder if you have it too. ADDA’s adult ADHD test is a good starting point to screen yourself for symptoms of ADHD.

Then you can seek a doctor’s advice for a possible diagnosis and let them know you have a family history of ADHD.

References

[1] Grimm, O., Kranz, T. M., & Reif, A. (2020). Genetics of ADHD: What Should the Clinician Know? Current psychiatry reports, 22(4), 18. https://doi.org/10.1007/s11920-020-1141-x

[2] Faraone, S. V., & Larsson, H. (2018, June 11). Genetics of attention deficit hyperactivity disorder. Molecular Psychiatry, 24(4), 562–575. https://doi.org/10.1038/s41380-018-0070-0

[3] Uchida, M., Driscoll, H., DiSalvo, M., Rajalakshmim, A., Maiello, M., Spera, V., & Biederman, J. (2021). Assessing the Magnitude of Risk for ADHD in Offspring of Parents with ADHD: A Systematic Literature Review and Meta-Analysis. Journal of attention disorders, 25(13), 1943–1948. https://doi.org/10.1177/1087054720950815

[4] Rubia K. (2018). Cognitive Neuroscience of Attention Deficit Hyperactivity Disorder (ADHD) and Its Clinical Translation. Frontiers in human neuroscience, 12, 100. https://doi.org/10.3389/fnhum.2018.00100

[5] Bayard, F., Nymberg Thunell, C., Abé, C., Almeida, R., Banaschewski, T., Barker, G., Bokde, A. L. W., Bromberg, U., Büchel, C., Quinlan, E. B., Desrivières, S., Flor, H., Frouin, V., Garavan, H., Gowland, P., Heinz, A., Ittermann, B., Martinot, J. L., Martinot, M. L. P., . . . Petrovic, P. (2018, August 14). Distinct brain structure and behavior related to ADHD and conduct disorder traits. Molecular Psychiatry, 25(11), 3020–3033. https://doi.org/10.1038/s41380-018-0202-6

[6] Blum, K., Chen, A. L., Braverman, E. R., Comings, D. E., Chen, T. J., Arcuri, V., Blum, S. H., Downs, B. W., Waite, R. L., Notaro, A., Lubar, J., Williams, L., Prihoda, T. J., Palomo, T., & Oscar-Berman, M. (2008). Attention-deficit-hyperactivity disorder and reward deficiency syndrome. Neuropsychiatric disease and treatment, 4(5), 893–918. https://doi.org/10.2147/ndt.s2627

[7] Ruff, M. E. (2005, September). Attention Deficit Disorder and Stimulant Use: An Epidemic of Modernity. Clinical Pediatrics, 44(7), 557–563. https://doi.org/10.1177/000992280504400701

[8] Rahman, M. S., Takahashi, N., Iwabuchi, T., Nishimura, T., Harada, T., Okumura, A., Takei, N., Nomura, Y., & Tsuchiya, K. J. (2021, September 24). Elevated risk of attention deficit hyperactivity disorder (ADHD) in Japanese children with higher genetic susceptibility to ADHD with a birth weight under 2000 g. BMC Medicine, 19(1). https://doi.org/10.1186/s12916-021-02093-3

[9] Grizenko, N., Fortier, M. E., Zadorozny, C., Thakur, G., Schmitz, N., Duval, R., & Joober, R. (2012). Maternal Stress during Pregnancy, ADHD Symptomatology in Children and Genotype: Gene-Environment Interaction. Journal of the Canadian Academy of Child and Adolescent Psychiatry = Journal de l’Academie canadienne de psychiatrie de l’enfant et de l’adolescent, 21(1), 9–15. https://pubmed.ncbi.nlm.nih.gov/22299010/

[10] Amiri, S., Malek, A., Sadegfard, M., & Abdi, S. (2012). Pregnancy-related maternal risk factors of attention-deficit hyperactivity disorder: a case-control study. ISRN pediatrics, 2012, 458064. https://doi.org/10.5402/2012/458064

[11] Stenseng, F., Hygen, B. W., & Wichstrøm, L. (2020). Time spent gaming and psychiatric symptoms in childhood: cross-sectional associations and longitudinal effects. European child & adolescent psychiatry, 29(6), 839–847. https://doi.org/10.1007/s00787-019-01398-2

[12] Cagigal, C., Silva, T., Jesus, M., & Silva, C. (2019). Does Diet Affect the Symptoms of ADHD? Current pharmaceutical biotechnology, 20(2), 130–136. https://doi.org/10.2174/1389201019666180925140733

[13] Hartman, C. A., Rommelse, N., van der Klugt, C. L., Wanders, R., & Timmerman, M. E. (2019). Stress Exposure and the Course of ADHD from Childhood to Young Adulthood: Comorbid Severe Emotion Dysregulation or Mood and Anxiety Problems. Journal of clinical medicine, 8(11), 1824. https://doi.org/10.3390/jcm8111824