Common autoimmune disorders 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 where the immune system ‘attacks’ the body incorrectly,” said the author, Timothy Nielsen, a research officer and doctoral student at the Children’s Hospital at Westmead Clinical School of the University of Sydney. The study was published Tuesday in JAMA Pediatrics.
The attack could lead to “a ‘multi-organ’ disorder like lupus, or an ‘organ-specific’ disorder like autoimmune thyroid disease (Hashimoto’s thyroiditis or Graves’ disease),” Nielsen said in an email.
Neural developmental disorders such as ADHD, learning disabilities and autism are caused by interruptions in the development of the fetal brain during pregnancy, Nielsen said. Previous research has linked autoimmune disorders in mothers with autism, obsessive-compulsive disorder and tics or Tourette syndrome in children, he said, but this is one of the first studies to investigate their role in ADHD.
“I hope these findings do not overemphasize women with autoimmune conditions,” said Dr. Jenny Radesky, developmental pediatrician, an assistant professor of pediatrics at Michigan Medicine CS Mott Children’s Hospital, who was not involved in the study, said.
“I treat a lot of children with ADHD, and these findings will not change how I deal with it,” Radesky said. ‘Although children with ADHD can be a handful, I like their expansive, curious thoughts and unique ways of seeing things.
“Mothers with an autoimmune disease may work to optimally control their condition during pregnancy, but autoimmune disease is not like smoking during pregnancy – another risk factor for ADHD – over which mothers have more direct control,” she said. added.
Large, longitudinal study
The study followed more than 63,000 full-term children born between 1 July 2000 and 31 December 2010 in New South Wales, Australia. Nielsen and his team identified 12,610 mothers with at least one of 35 common autoimmune disorders. Each of the expectant mothers has a diagnosis code for an autoimmune disorder in their linked hospitalization reports.
A child was determined to have ADHD if there was a hospital diagnosis of ADHD or a report of the prescribed or filled prescription for stimulants.
All 12,610 offspring diagnosed with ADHD over the age of 3 were included in the study and then matched four children of the same age with mothers without any autoimmune disorders. Both sets of children were followed until the end of 2014.
The study also conducted a meta-analysis of existing research on the topic.
The results combined that a diagnosis of any autoimmune disease, type 1 diabetes, rheumatic fever or rheumatic carditis (inflammation of the heart muscle), psoriasis and hyperthyroidism was associated with an increased risk of ADHD in the child at later ages.
Autoimmune diseases and inflammation
Exactly how a mother’s autoimmune disorder can affect her unborn baby is not yet known. Researchers believe that maternal pathways – mothers that attack the mother’s body – cross through the placenta. Inflammatory molecules can do the same.
Once there, the chronic inflammation can alter the development of the fetus’ brain, possibly by affecting the innate immune cells in the developing baby’s brain. Or perhaps inflammation changes epigenetic markers – the chemicals that turn genes on or off – on important neurodevelopmental genes in the fetus.
According to the study, another theory is that inflammation develops the formation and function of synapses in the baby’s brain. Synapses are the small sacs of space between two cells that allow the cells to transmit and communicate messages.
“These changes can directly lead to ADHD symptoms, or it can make the child more vulnerable to environmental risk factors,” Nielsen said.
Previous research has found that women with autoimmune diseases that are poorly controlled by medication or other treatments can be a risk factor for poor pregnancy outcomes, such as failure to grow properly and premature birth, Nielsen said.
“Our team is currently researching the causal mechanisms underlying the link between autoimmune disease and ADHD,” he said. This may shed light on whether the “severity of illness, symptoms, medication use, or other inflammatory factors alters this risk of ADHD.”
knowledge is power
An expectant mother who has an autoimmune disorder is only one of the many risk factors for any neurodevelopmental disorder in children, Nielsen emphasized, “but understanding risk and expression of disease is essential if we are to prevent disease and treat.”
The knowledge of such an association can empower both women and their healthcare providers to ’emphasize the importance of high quality multidisciplinary care in managing autoimmune conditions before and during pregnancy,’ Nielsen said.
“This includes good care before conception and avoiding pregnancy if disease activity is not well controlled,” he said.
Beyond that, it is nobody’s fault if a child develops a disorder based on the parent’s medical condition, experts emphasize.
“Sometimes parents will persevere through feelings of guilt about a child’s ADHD as ‘guilt,'” developmental pediatrician Radesky said.
“When that happens, I try to divert their mental energy to understanding their child’s unique mix of strengths and challenges, why the child is behaving the way they are acting, and how to plead for support,” she said.