Parents pass all kinds of things down to their kids - red hair, bad eyesight, maybe even a taste for spicy food. Sometimes, the health conditions of a parent can make an impact on the child. This is the case with autoimmune disorders in mothers, and ADHD in their children. New research, published in JAMA Pediatrics, explored the connection.
Typically, when we think of parents passing things down, it is because of genetics, like blood type, where the child’s blood type is a combination of the parents’. That’s not what researchers think is going on with the autoimmunity/ADHD connection. Genetics does play a role, but new research points to the time a fetus spends inside its mother as a contributing factor.
Timothy Nielsen, MPH, who authored a study showing the link explored the theory that “inflammation during pregnancy can change how the unborn child’s brain develops.” He explained, in a statement to Medical Daily, that researchers have already shown that mom’s inflammation can affect the baby, but the big question is how. Mr. Nielsen said some possibilities are that the inflammation in mom creates proteins that affect the fetus, or maybe the inflammation changes the way the fetus’ genes are expressed.
Mr. Nielsen studied 63,050 kids and their mothers in New South Wales, Australia. The researchers found that mothers with “any autoimmune disease, type 1 diabetes, rheumatic fever or rheumatic carditis, or psoriasis,” were more likely to have kids that developed ADHD. Of the total 63,050 kids, 12,610 had mothers with autoimmune conditions. Their outcomes were compared to the other 50,440 children, whose mothers did not have autoimmune conditions, to see which of the kids would go on to develop ADHD. Mothers with an autoimmune condition were 30% more likely to have a child with ADHD than mothers without an autoimmune condition.
What is ADHD?
ADHD, or attention deficit hyperactivity disorder, is one of the most common neurodevelopmental conditions. Kids with ADHD can have trouble focusing or behaving and it can be characterized by excessive fidgeting, squirming, difficulty getting along with others, and poor impulse control.
Mr. Nielen described how inflammation plays a role. “Ideally, the body’s inflammatory response triggers acute inflammation in response to a threat, like an infected cut, which resolves quickly,” said Mr. Nielsen. For example, think about the skin around an infected papercut; it’s red, tight, maybe even warm, and painful. That represents the body ramping up the immune system to drive out any attackers.
But, especially with autoimmunity, sometimes the signals get crossed and the body attacks itself. And autoimmunity isn’t the only cause of, or a link to, inflammation. Other factors connected to a state of chronic inflammation, Mr. Nielsen said, “physical inactivity, obesity, poor diet, chronic stress, poor sleep, smoking and pollution,” could all cause chronic inflammation. A review study published in Translational Psychiatry, the same week as the JAMA Pediatrics study, found that those issues in mom which were linked to child’s ADHD included asthma, autoimmune disease, obesity, preeclampsia, smoking, and stress.
What to do?
Autoimmunity is just one factor in why a child may develop a neurodevelopmental disorder like ADHD. So, expectant mothers shouldn’t worry too much. “Our main message for women is to emphasize the importance of good multidisciplinary care to manage autoimmune conditions before and during pregnancy,” said Mr. Nielsen. As with all health conditions, the best thing is to be on top of them. Mr. Nielsen did mention that some mothers might want to consider delaying pregnancy until their condition is better controlled. Obviously, this was broad advice and does not apply to everyone.
“I want to emphasize that our results should not be a cause for concern for expectant mothers with autoimmune conditions,” said Mr. Nielsen. He explained that conditions like ADHD have a variety of factors, and maternal health is just one part.
Does dad play a role?
It takes two to make a baby, but only maternal autoimmunity seems to matter. Mr. Nielsen did not look at fathers, as they weren’t included in the dataset he used, but other studies have found no link between autoimmunity issues in dad and the fetus. Most of the theories of why maternal autoimmunity can lead to neurodevelopmental issues revolve around fetal exposure to something while in-utero, ruling dad out as a contributing factor.
Research continues. Mr. Nielsen is currently working to better understand how maternal autoimmunity contributes to neurodevelopmental conditions in kids. “With that work, we hope to be able to provide better information,” he said. In the Translational Psychiatry review, researchers found links between maternal depression, which can be linked to inflammation, and Tourettes Syndrome. Parental socioeconomic status is also linked with ADHD in kids.