Common autoimmune diseases include type 1 diabetes, ulcerative colitis, Crohn’s and celiac disease, psoriasis, multiple sclerosis and rheumatoid arthritis, to name a few.
“Autoimmune diseases are disorders in which the immune system ‘attacks’ the body incorrectly,” said study author Timothy Nielsen, a researcher and doctoral student at Children’s Hospital at Westmead Clinical School at the University of Sydney. The study was published on Tuesday in JAMA Pediatrics.
The attack can result in “a ‘multiple organ’ disorder, such as lupus, or an ‘organ-specific’ disorder, such as an autoimmune thyroid disease (Hashimoto’s thyroiditis or Graves’ disease),” said Nielsen. mail.
Neurodevelopmental disorders, such as ADHD, learning disabilities and autism are caused by disruptions in fetal brain development during pregnancy, said Nielsen. Previous research has linked autoimmune disorders in mothers with autism, obsessive-compulsive disorder and tics or Tourette’s syndrome in children, he said, but this is one of the first studies to examine its role in ADHD.
“I hope these findings don’t stress women with autoimmune diseases too much,” said developmental pediatrician Dr. Jenny Radesky, assistant professor of pediatrics at Children’s Hospital CS Mott in Michigan Medicine, who was not involved in the study.
“I treat many children with ADHD, and these findings would not change the way I treat them,” said Radesky. “Although children with ADHD can be difficult, I love their expansive and curious little minds and their unique ways of looking at things.
“Mothers with autoimmune diseases can work to have optimal control of their condition during pregnancy, but autoimmune diseases are not like smoking during pregnancy – another risk factor for ADHD – over which mothers have control. more direct, ”she added.
Large longitudinal study
The study followed more than 63,000 children born at term between July 1, 2000 and December 31, 2010, in New South Wales, Australia. Nielsen and his team identified 12,610 mothers with at least one of the 35 common autoimmune diseases. Each of the pregnant women had a diagnostic code for an autoimmune disorder in their linked hospital records.
A child was determined to have ADHD if there was a hospital diagnosis of ADHD or a record of a prescription prescribed or filled with stimulants.
All 12,610 offspring who were diagnosed with ADHD over the age of 3 were included in the study and then matched to four children of the same age with mothers without any autoimmune diseases. Both sets of children were followed up until the end of 2014.
The study also conducted a meta-analysis of existing research on the topic.
Combined, the results showed that the diagnosis of any autoimmune disease, type 1 diabetes, rheumatic fever or rheumatic carditis (inflammation of the heart muscle), psoriasis and hyperthyroidism were associated with an increased risk of ADHD in children at later ages.
Autoimmune diseases and inflammation
It is not yet known exactly how the mother’s autoimmune disorder can affect her baby. The researchers believe that maternal autoantibodies – those that attack the mother’s body – cross through the placenta. Inflammatory molecules can do the same.
Once there, chronic inflammation can alter fetal brain development, possibly affecting innate immune cells in the developing baby’s brain, the study said. Or perhaps inflammation alters epigenetic markers – the chemicals that turn genes on or off – in key neurodevelopmental genes in the fetus.
Another theory, says the study, is that inflammation affects the formation and function of synapses in the baby’s developing brain. Synapses are small pockets of space between two cells that allow cells to transmit messages and communicate.
“These changes can lead directly to ADHD symptoms or can make a child more vulnerable to environmental risk factors,” said Nielsen.
Previous research has found that women with autoimmune diseases poorly controlled by medications or other treatments can be a risk factor for poor pregnancy outcomes, such as poor growth and premature birth, said Nielsen.
“Our team is currently working on researching the causal mechanisms that underlie the association between autoimmune diseases and ADHD,” he said, which may shed light on whether “disease severity, symptoms, medication use or other inflammatory factors modify this risk. of ADHD. “
Knowledge is power
A future mother with an autoimmune disorder is just one of many risk factors for any childhood neurodevelopmental disorder, Nielsen emphasized, “but understanding the risk and expression of the disease is essential if we are to prevent and treat the disease.”
Having knowledge of such an association can empower women and their health care providers to “emphasize the importance of high quality multidisciplinary care to control autoimmune diseases before and during pregnancy,” said Nielsen.
“This includes good pre-conception care and possibly avoiding pregnancy when disease activity is not well controlled,” he said.
Furthermore, it is no one’s fault if a child develops a disorder based on the parents’ medical condition, experts emphasize.
“Sometimes parents persist in their guilt that a child’s ADHD is their ‘fault’. “said pediatrician Radesky.
“When that happens, I try to redirect their mental energy to understand their children’s unique combination of strengths and challenges, why the child behaves this way and how to advocate for support,” she said.