Table of ContentsView AllTable of ContentsCommon Causes of ADHDGeneticsIllnesses and InjuriesToxinsExposure to Substances in UteroNext in ADHD GuideTesting for ADHD
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Table of Contents
Common Causes of ADHD
Genetics
Illnesses and Injuries
Toxins
Exposure to Substances in Utero
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Attention-deficit hyperactivity disorder(ADHD) is a common neurobehavioral condition that causes inattention, hyperactivity, and impulsivity. It is usually diagnosed during childhood, but it can also affect adults. If you’ve spent any amount of time on social media lately, you’ve probably noticed the growing recognition of how ADHD affects people from childhood and into adulthood.
This increased knowledge has also come with a greater understanding of ADHD as a form ofneurodiversityand not a disorder that needs to be “cured.” If you have ADHD, it means that your brain processes information differently. People with ADHD face challenges because they are expected to conform to expectations created for a neurotypical society.
The exact causes ofADHDaren’t known. However, researchers suspect there may be several factors that determine whether someone might develop ADHD. Genetics, toxins, exposure to substances during prenatal development, and certain medical conditions can all play a role.
At a GlanceADHD is complex, and there is no single cause. There are, however, certain factors that might make a person more likely to have ADHD characteristics. Genetics plays a big role, but other variables like substance use, exposure to toxins, and illnesses can increase the likelihood of having it.Regardless of the causes, people with ADHD can succeed and thrive with the right support and accommodations. If you or your child have ADHD, talk to your doctor about which options might be right for you.
At a Glance
ADHD is complex, and there is no single cause. There are, however, certain factors that might make a person more likely to have ADHD characteristics. Genetics plays a big role, but other variables like substance use, exposure to toxins, and illnesses can increase the likelihood of having it.Regardless of the causes, people with ADHD can succeed and thrive with the right support and accommodations. If you or your child have ADHD, talk to your doctor about which options might be right for you.
ADHD is complex, and there is no single cause. There are, however, certain factors that might make a person more likely to have ADHD characteristics. Genetics plays a big role, but other variables like substance use, exposure to toxins, and illnesses can increase the likelihood of having it.
Regardless of the causes, people with ADHD can succeed and thrive with the right support and accommodations. If you or your child have ADHD, talk to your doctor about which options might be right for you.
Verywell / Brianna Gilmartin
Researchers believe that there are many different causes of ADHD. Some of the factors that can contribute or increase the risk of developing ADHD include:
What Does Not Cause ADHD
Whether you have recently beendiagnosed with ADHDor have been living with ADHD for many years, a question almost all adults ask is: “Will my children have ADHD, too?” The answer is: It depends.
ADHD is primarily a hereditary disorder. It is estimated that the percentage of genetic contribution to ADHD is an estimated 74%.
Despite this strong genetic link, having ADHD doesn’t automatically mean you’ll pass it on to your child. This is because it is a combination of genes and environmental factors that determine whether a child develops ADHD.
Children can inherit ADHD genes without them being activated. For example, one research study found that only one-third of fathers with ADHD had children that also developed ADHD.
If a child inherits ADHD from a parent, the parent’sADHD presentation or subtype(inattentive, hyperactive-impulsive orcombined) will not influence the ADHD presentation of the child.
To date, several gene candidates have been found in families who demonstrate ADHD. However, scientists feel that it is not one particular gene but the interaction of several of these genes and the environment that causeADHD symptomsto manifest.
ADHD is not a sex-linked condition. In other words, ADHD does not occur only in males and is thus not passed down only from a father to the children. Some people think, “It’s only fathers who can have ADHD, and if the dad doesn’t have ADHD then the child can’t possibly have it.” This is inaccurate.
Although ADHD is diagnosed more frequently in males than females, it is important to understand that people of all genders can have ADHD.
Illnesses and Injuries
Illnesses such as meningitisor encephalitis can result in learning and attention problems.
A small percentage of people experience ADHD symptoms as a result of brain damage, such as an early brain injury, trauma, or another impediment to normal brain development.
One study published inJAMA Pediatricsfound that children with a history of traumatic brain injuries, even if less severe, have an increased risk of developing ADHD for as long as 10 years after the injury.
Being exposed to certain environmental toxins during childhood can increase the risk that a child will develop ADHD.
Exposure to lead (even low levels) can result in hyperactivity and inattention. Lead can be found a variety of places, such as in the paint of homes built before 1978 or previously in gasoline.
A gestational parent’s health and habits during pregnancy can also play a role in the development of ADHD. Poor nutrition and infections during pregnancy can increase the risk of ADHD, for example.
There’s also evidence that using some substances during pregnancy increases the risk that the child will develop ADHD.
Smoking
A 2018 study published inPediatricsfound a significant relationship between smoking during pregnancy and the likelihood of a child having ADHD.The risk of ADHD was greater in children whose mothers smoked heavily. The study couldn’t conclude that smoking causes ADHD, but it did indicate that a correlation exists.
Alcohol
Some studies have found that parents who drink during pregnancy are more likely to have children with ADHD. A 2018 study found that consuming four or more drinks at a time, or regular low to moderate alcohol, use was associated with a significant increase in the chances that a child would later have ADHD.
A 2017 study, however, found that there was no link between maternal alcohol use and a clinical ADHD diagnosis in children. This study suggested that children may develop some symptoms of ADHD if their parent used alcohol during pregnancy, but they didn’t necessarily qualify for an ADHD diagnosis.
10 Risks of Smoking During Pregnancy
Takeaways
It’s likely that ADHD stems from a variety of causes. Someone who has a genetic predisposition, for example, may encounter environmental factors that also contribute to the development of ADHD.Toxins, exposure to substances during prenatal development, certain types of infections, and brain injuries can increase the risk that a person will develop ADHD.
Researchers continue to learn more about the potential causes and risk factors for ADHD. While the exact causes may not be known, it is important to know that there are effective treatments available that can help you or your child manage the symptoms of the condition. Talk to your healthcare provider if you think you or your child may have ADHD to learn more about what treatment options might work best for you.
How Is ADHD Diagnosed?
13 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Faraone SV, Larsson H.Genetics of attention deficit hyperactivity disorder.Mol Psychiatry. 2019;24(4):562-575. doi:10.1038/s41380-018-0070-0National Institutes of Health.The ADHD Genetic Research Study.Starck M, Grünwald J, Schlarb AA.Occurrence of ADHD in parents of ADHD children in a clinical sample.Neuropsychiatr Dis Treat. 2016;12:581-8. doi:10.2147/NDT.S100238Martin J, Taylor MJ, Rydell M, et al.Sex-specific manifestation of genetic risk for attention deficit hyperactivity disorder in the general population.J Child Psychol Psychiatry. 2018;59(8):908-916. doi:10.1111/jcpp.12874Hadzic E, Sinanovic O, Memisevic H.Is bacterial meningitis a risk factor for developing attention deficit hyperactivity disorder.Isr J Psychiatry Relat Sci. 2017;54(2):54-57.Chou IC, Lin CC, Kao CH.Enterovirus encephalitis increases the risk of attention deficit hyperactivity disorder: A Taiwanese population-based case-control study.Medicine (Baltimore). 2015;94(16):e707. doi:10.1097/MD.0000000000000707Asarnow RF, Newman N, Weiss RE, Su E.Association of attention-deficit/hyperactivity disorder diagnoses with pediatric traumatic brain injury: A meta-analysis.JAMA Pediatr. 2021;175(10):1009-1016. doi:10.1001/jamapediatrics.2021.2033Narad ME, Kennelly M, Zhang N, et al.Secondary attention-deficit/hyperactivity disorder in children and adolescents 5 to 10 years after traumatic brain injury.JAMA Pediatr. 2018;172(5):437. doi:10.1001/jamapediatrics.2017.5746Donzelli G, Carducci A, Llopis-gonzalez A, et al.The association between lead and attention-deficit/hyperactivity disorder: A systematic review.Int J Environ Res Public Health. 2019;16(3) doi:10.3390/ijerph16030382Huang L, Wang Y, Zhang L, et al.Maternal smoking and attention-deficit/hyperactivity disorder in offspring: a meta-analysis.Pediatrics. 2018;141(1):e20172465. doi:10.1542/peds.2017-2465Pagnin D, Zamboni Grecco ML, Furtado EF.Prenatal alcohol use as a risk for attention-deficit/hyperactivity disorder.Eur Arch Psychiatry Clin Neurosci. 2019;269(6):681-687. doi:10.1007/s00406-018-0946-7Eilertsen EM, Gjerde LC, Reichborn-Kjennerud T, et al.Maternal alcohol use during pregnancy and offspring attention-deficit hyperactivity disorder (ADHD): a prospective sibling control study.Int J Epidemiol. 2017;46(5):1633-1640. doi:10.1093/ije/dyx067Dark C, Homman-ludiye J, Bryson-richardson RJ.The role of ADHD associated genes in neurodevelopment.Dev Biol. 2018;438(2):69-83. doi:10.1016/j.ydbio.2018.03.023
13 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Faraone SV, Larsson H.Genetics of attention deficit hyperactivity disorder.Mol Psychiatry. 2019;24(4):562-575. doi:10.1038/s41380-018-0070-0National Institutes of Health.The ADHD Genetic Research Study.Starck M, Grünwald J, Schlarb AA.Occurrence of ADHD in parents of ADHD children in a clinical sample.Neuropsychiatr Dis Treat. 2016;12:581-8. doi:10.2147/NDT.S100238Martin J, Taylor MJ, Rydell M, et al.Sex-specific manifestation of genetic risk for attention deficit hyperactivity disorder in the general population.J Child Psychol Psychiatry. 2018;59(8):908-916. doi:10.1111/jcpp.12874Hadzic E, Sinanovic O, Memisevic H.Is bacterial meningitis a risk factor for developing attention deficit hyperactivity disorder.Isr J Psychiatry Relat Sci. 2017;54(2):54-57.Chou IC, Lin CC, Kao CH.Enterovirus encephalitis increases the risk of attention deficit hyperactivity disorder: A Taiwanese population-based case-control study.Medicine (Baltimore). 2015;94(16):e707. doi:10.1097/MD.0000000000000707Asarnow RF, Newman N, Weiss RE, Su E.Association of attention-deficit/hyperactivity disorder diagnoses with pediatric traumatic brain injury: A meta-analysis.JAMA Pediatr. 2021;175(10):1009-1016. doi:10.1001/jamapediatrics.2021.2033Narad ME, Kennelly M, Zhang N, et al.Secondary attention-deficit/hyperactivity disorder in children and adolescents 5 to 10 years after traumatic brain injury.JAMA Pediatr. 2018;172(5):437. doi:10.1001/jamapediatrics.2017.5746Donzelli G, Carducci A, Llopis-gonzalez A, et al.The association between lead and attention-deficit/hyperactivity disorder: A systematic review.Int J Environ Res Public Health. 2019;16(3) doi:10.3390/ijerph16030382Huang L, Wang Y, Zhang L, et al.Maternal smoking and attention-deficit/hyperactivity disorder in offspring: a meta-analysis.Pediatrics. 2018;141(1):e20172465. doi:10.1542/peds.2017-2465Pagnin D, Zamboni Grecco ML, Furtado EF.Prenatal alcohol use as a risk for attention-deficit/hyperactivity disorder.Eur Arch Psychiatry Clin Neurosci. 2019;269(6):681-687. doi:10.1007/s00406-018-0946-7Eilertsen EM, Gjerde LC, Reichborn-Kjennerud T, et al.Maternal alcohol use during pregnancy and offspring attention-deficit hyperactivity disorder (ADHD): a prospective sibling control study.Int J Epidemiol. 2017;46(5):1633-1640. doi:10.1093/ije/dyx067Dark C, Homman-ludiye J, Bryson-richardson RJ.The role of ADHD associated genes in neurodevelopment.Dev Biol. 2018;438(2):69-83. doi:10.1016/j.ydbio.2018.03.023
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Faraone SV, Larsson H.Genetics of attention deficit hyperactivity disorder.Mol Psychiatry. 2019;24(4):562-575. doi:10.1038/s41380-018-0070-0National Institutes of Health.The ADHD Genetic Research Study.Starck M, Grünwald J, Schlarb AA.Occurrence of ADHD in parents of ADHD children in a clinical sample.Neuropsychiatr Dis Treat. 2016;12:581-8. doi:10.2147/NDT.S100238Martin J, Taylor MJ, Rydell M, et al.Sex-specific manifestation of genetic risk for attention deficit hyperactivity disorder in the general population.J Child Psychol Psychiatry. 2018;59(8):908-916. doi:10.1111/jcpp.12874Hadzic E, Sinanovic O, Memisevic H.Is bacterial meningitis a risk factor for developing attention deficit hyperactivity disorder.Isr J Psychiatry Relat Sci. 2017;54(2):54-57.Chou IC, Lin CC, Kao CH.Enterovirus encephalitis increases the risk of attention deficit hyperactivity disorder: A Taiwanese population-based case-control study.Medicine (Baltimore). 2015;94(16):e707. doi:10.1097/MD.0000000000000707Asarnow RF, Newman N, Weiss RE, Su E.Association of attention-deficit/hyperactivity disorder diagnoses with pediatric traumatic brain injury: A meta-analysis.JAMA Pediatr. 2021;175(10):1009-1016. doi:10.1001/jamapediatrics.2021.2033Narad ME, Kennelly M, Zhang N, et al.Secondary attention-deficit/hyperactivity disorder in children and adolescents 5 to 10 years after traumatic brain injury.JAMA Pediatr. 2018;172(5):437. doi:10.1001/jamapediatrics.2017.5746Donzelli G, Carducci A, Llopis-gonzalez A, et al.The association between lead and attention-deficit/hyperactivity disorder: A systematic review.Int J Environ Res Public Health. 2019;16(3) doi:10.3390/ijerph16030382Huang L, Wang Y, Zhang L, et al.Maternal smoking and attention-deficit/hyperactivity disorder in offspring: a meta-analysis.Pediatrics. 2018;141(1):e20172465. doi:10.1542/peds.2017-2465Pagnin D, Zamboni Grecco ML, Furtado EF.Prenatal alcohol use as a risk for attention-deficit/hyperactivity disorder.Eur Arch Psychiatry Clin Neurosci. 2019;269(6):681-687. doi:10.1007/s00406-018-0946-7Eilertsen EM, Gjerde LC, Reichborn-Kjennerud T, et al.Maternal alcohol use during pregnancy and offspring attention-deficit hyperactivity disorder (ADHD): a prospective sibling control study.Int J Epidemiol. 2017;46(5):1633-1640. doi:10.1093/ije/dyx067Dark C, Homman-ludiye J, Bryson-richardson RJ.The role of ADHD associated genes in neurodevelopment.Dev Biol. 2018;438(2):69-83. doi:10.1016/j.ydbio.2018.03.023
Faraone SV, Larsson H.Genetics of attention deficit hyperactivity disorder.Mol Psychiatry. 2019;24(4):562-575. doi:10.1038/s41380-018-0070-0
National Institutes of Health.The ADHD Genetic Research Study.
Starck M, Grünwald J, Schlarb AA.Occurrence of ADHD in parents of ADHD children in a clinical sample.Neuropsychiatr Dis Treat. 2016;12:581-8. doi:10.2147/NDT.S100238
Martin J, Taylor MJ, Rydell M, et al.Sex-specific manifestation of genetic risk for attention deficit hyperactivity disorder in the general population.J Child Psychol Psychiatry. 2018;59(8):908-916. doi:10.1111/jcpp.12874
Hadzic E, Sinanovic O, Memisevic H.Is bacterial meningitis a risk factor for developing attention deficit hyperactivity disorder.Isr J Psychiatry Relat Sci. 2017;54(2):54-57.
Chou IC, Lin CC, Kao CH.Enterovirus encephalitis increases the risk of attention deficit hyperactivity disorder: A Taiwanese population-based case-control study.Medicine (Baltimore). 2015;94(16):e707. doi:10.1097/MD.0000000000000707
Asarnow RF, Newman N, Weiss RE, Su E.Association of attention-deficit/hyperactivity disorder diagnoses with pediatric traumatic brain injury: A meta-analysis.JAMA Pediatr. 2021;175(10):1009-1016. doi:10.1001/jamapediatrics.2021.2033
Narad ME, Kennelly M, Zhang N, et al.Secondary attention-deficit/hyperactivity disorder in children and adolescents 5 to 10 years after traumatic brain injury.JAMA Pediatr. 2018;172(5):437. doi:10.1001/jamapediatrics.2017.5746
Donzelli G, Carducci A, Llopis-gonzalez A, et al.The association between lead and attention-deficit/hyperactivity disorder: A systematic review.Int J Environ Res Public Health. 2019;16(3) doi:10.3390/ijerph16030382
Huang L, Wang Y, Zhang L, et al.Maternal smoking and attention-deficit/hyperactivity disorder in offspring: a meta-analysis.Pediatrics. 2018;141(1):e20172465. doi:10.1542/peds.2017-2465
Pagnin D, Zamboni Grecco ML, Furtado EF.Prenatal alcohol use as a risk for attention-deficit/hyperactivity disorder.Eur Arch Psychiatry Clin Neurosci. 2019;269(6):681-687. doi:10.1007/s00406-018-0946-7
Eilertsen EM, Gjerde LC, Reichborn-Kjennerud T, et al.Maternal alcohol use during pregnancy and offspring attention-deficit hyperactivity disorder (ADHD): a prospective sibling control study.Int J Epidemiol. 2017;46(5):1633-1640. doi:10.1093/ije/dyx067
Dark C, Homman-ludiye J, Bryson-richardson RJ.The role of ADHD associated genes in neurodevelopment.Dev Biol. 2018;438(2):69-83. doi:10.1016/j.ydbio.2018.03.023
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