Is ADHD Genetic or Environmental? 9 Factors That May Affect ADHD

But are those concerns valid? Learn more about whether there are any environmental factors suspected of causing or contributing to ADHD and what you can do to protect your child from these effects.

Toxins and ADHD

Exposure to toxins in utero or in early childhood could potentially be a cause or risk factor for ADHD. Some of the toxins that researchers have explored due to their association with ADHD include:

Lead
Mercury
Pesticides

Lead, in particular, has been shown to cause damage to developing brains. Some of the symptoms associated with lead exposure are similar to those of ADHD, including difficulty maintaining attention and certain types of behavioral issues. People who live in an area with a high risk for lead exposure should discuss their concerns with their health care provider.

Food Additives and ADHD

One theory that has gained in popularity over the years is that food additives can cause or exacerbate ADHD. Specifically, food dyes and preservatives have been suspected of contributing to the disorder since the 1970s. However, there is little scientific evidence linking ADHD to consuming food additives, and it is not thought to be a possible cause.

Cutting certain additives out of a child’s diet could potentially improve symptoms if the child has an allergy, but severely restricting diet as a treatment for ADHD is not recommended. Some parents may still choose to minimize food dyes and preservatives in their child’s diet, however, if they observe that consuming these ingredients seems to increase hyperactivity or lack of focus.

Psychosocial Factors and ADHD

A number of studies have focused on how certain psychological and social (or “psychosocial”) aspects influence the development of ADHD. In broader terms, they’ve attempted to look more closely at the conditions in which a child is raised and whether that might play a role in their risk for ADHD.

Some of the psychosocial factors which have been associated with ADHD include:

Maternal depression
Lower household income
A less-stimulating and supportive home environment

It’s still unclear exactly how much influence these factors have on ADHD development and the prevalence of symptoms of ADHD in adults and children. Research suggests that the effects may lessen over time.

Brain Injury and ADHD

As more people have become aware of the long-term effects of concussions and other head trauma in children, there’s been an increased interest in studying the link between brain injuries and ADHD. Some of the studies have resulted in substantial findings. For example, one found that 62% of children in a study who sustained a traumatic brain injury (TBI) developed ADHD, compared to just 15% among those without a TBI.

This suggests a fairly clear connection between brain damage and ADHD. However, more research is needed to understand whether there are differences between TBI-related ADHD and ADHD caused by other types of environmental or genetic factors.

Maternal Drug and Alcohol Use and ADHD

Studies have found that children exposed to opiates and other illicit substances in utero had a higher risk of developing ADHD. Similar research has been conducted on in-utero alcohol exposure, which one study finding that low to moderate alcohol consumption at any time during pregnancy was associated with five times the risk of childhood ADHD.

An important factor that some researchers have noted in their findings is that higher rates of ADHD have been found among adults with substance use disorder. This means that children exposed to drugs or alcohol in utero may also be genetically predisposed to ADHD.

Is ADHD Genetic?

Speaking of genetics, there is a lot of evidence that points to hereditary factors being significant contributors to ADHD. In fact, about a third of all fathers who had ADHD as a child have a child of their own with ADHD, and occurrence of ADHD has been noted in identical twins. Children with ADHD are four times more likely to have a relative with ADHD compared to children without the disorder.

The statistic used to define how much genes influence our traits is called heritability. For ADHD, the heritability factor is placed at 0.77 (on a scale of 0 to 1), which is about the same as bipolar disorder or schizophrenia. According to this data, it’s clear that genetics definitely play a role in how likely someone is to have ADHD.

When it comes down to it, there isn’t one simple, root cause of ADHD that scientists can point to. Instead, it’s likely a combination of different factors, including genetics and environment, that influence whether someone develops this disorder.

If you’re struggling with symptoms that you think may be related to ADHD, get in touch with us at Done. After a simple, one-minute assessment, we’ll put you in touch with one of our board-certified ADHD clinicians so you can get a full assessment and an accurate diagnosis. We offer ADHD treatment for adults and children along with 24/7 access to our care team to help you manage your symptoms on a daily basis.