Is There a Connection Between Thyroid Disorders and Autism?

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Autism is a common condition, and yet despite its wide prevalence, there’s a lot we do not know about it. Scientists are still working on studies that would elucidate Autism and underlying mechanisms associated with the condition.

The exact cause of the condition is unknown, but various factors are associated with its development.

Could thyroid disorders contribute to Autism?

What is Autism?

While all of us have heard of Autism or have come across someone who has it, the sheer nature of the condition is not clear to many.

The reason behind this could be the fact that Autism is strongly misunderstood. Various misconceptions about the condition prevent us from fully understanding everything it entails.

In order to discuss the potential relationship between thyroid disorders and Autism, it’s necessary to address the condition itself.

Autism is defined as a complex neurobehavioral condition indicated by impairments in social interaction, communication skills, and language development in combination with repetitive behaviors.

In other words, Autism affects the way an affected patient perceives the world around them, thinks, and behaves. The condition makes it difficult for the affected person to socialize and communicate with others.

How common is Autism?

Have you ever wondered just how common Autism really is?

The latest figures show that the prevalence of Autism in the United States increased by 15% over a two-year period.

The report which was published by the CDC involved data from 11 regional monitoring sites that are a part of the Autism and Developmental Disabilities Monitoring (ADDM) Network[i].

The numbers show that one in 59 children in the US is diagnosed with an autism spectrum disorder. The condition is more prevalent among boys than in girls. According to the report, one in 37 boys has Autism, while one in 151 girls develop the condition. In other words, boys are four times as likely as girls to be diagnosed with Autism.

While Autism can be reliably diagnosed at the age of two, most children are diagnosed with the disorder after age four. Numbers also reveal that 31% of children with Autism also have an intellectual disability.

Although Autism affects all people regardless of the socioeconomic status, religion, and ethnicity, the report shows that minority groups tend to be diagnosed later and less often[ii] than their counterparts.

Thyroid disorders and Autism

The exact cause of Autism is still unknown. In fact, the condition has no single known cause as it is theorized that both genetics and the environment play a role in the development of Autism.

Scientists are still trying to discover various factors that contribute to the onset of Autism and conditions that could be connected to it.

Is thyroid dysfunction one of them? While studies on this subject are limited, current evidence says yes.

Fyre et al. carried out a study to inspect a relationship between Autism and thyroid dysfunction in children. The study reports that thyroid dysfunction is frequently found in children with Autism. For the purpose of the research, scientists measured blocking and binding folate receptor α autoantibodies (FRAAs), TSH, free thyroxine (fT4), total triiodothyronine (tT3), reverse T3 (rT3), TRH and other metabolites in 87 children with Autism. Of these, 84 kids also underwent behavior and cognition testing.

For reference, FRAAs are prevalent in children with Autism. Results showed that thyroid problems were common in subjects, and they could be related to blocking FRAA.

In other words, dysfunction of the butterfly-shaped gland in children with Autism is strongly associated with an autoimmune disorder affecting folate receptor. The study also showed that high expression of folate receptor α in the early fetal thyroid suggests that fetal and neonatal exposure to maternal FRAAs could affect the development of the thyroid and may play a role in the pathology of Autism[iii].

Some reports reveal that many health care providers miss the diagnosis of hypothyroidism in children with Autism because they rely on unreliable thyroid blood tests.

Unfortunately, missing hypothyroidism diagnosis leaves one of the most important factors in autism etiology untreated.

The severity of the problem is best depicted by the report that 42 out of 62 children diagnosed with Autism are also hypothyroid. That could be due to the fact that thyroid hormone deficiency in the early development could cause damage to the nervous system and symptoms of Autism are likely to ensue.

Even though more research is needed to elucidate the mechanisms that connect thyroid and Autism, it’s worth to mention that having the right amount of thyroid hormone is crucial for our health, especially for brain function and formation which begins in the womb.

During the first trimester of pregnancy, the growing fetus depends on the mother’s thyroid hormone for its growth and development. In later stages of pregnancy, the fetus can produce thyroid hormones on its own, but it still relies on their mothers to some extent.

The brain develops under the influence of T4 and T3 regulating the proliferation, differentiation, and migration of neurons in specific regions of the brain. That could explain why a deficiency of thyroid hormones either in a child or in mother could impair brain development and contribute to Autism.

Thyroid dysfunction and Autism in children are more connected than we think. For example, both the thyroid and the brain are susceptible to the growing burden of environmental toxins like mercury and lead.

Exposure to toxins in the environment has a negative impact on the developing brain, partly due to their impact on the butterfly-shaped gland. Decreased function of the thyroid can impair the detox process, which causes a secondary accumulation of toxins.

Gluten sensitivity is yet another point of connection between thyroid dysfunction and Autism. That’s why a gluten-free diet can be helpful for children with Autism, and it also helps manage symptoms of hypothyroidism.

Symptoms shared by both conditions

As seen above, thyroid dysfunction and Autism have some important things in common.

But, what many people don’t know is that they also share some symptoms. Signs and symptoms that are associated with both Autism and thyroid dysfunction in children include[iv]:

  • Bed Wetting
  • Prolonged jaundice
  • Weak concentration and processing
  • Fears, anxiety, and depression
  • Feeding and eating problems
  • Weight gain or experiencing difficulty to gain weight
  • Poor bone development
  • Intolerance to cold
  • Cold extremities
  • Poor muscle tone
  • Frequent allergies and infections
  • Gastrointestinal problems
  • Bald spots and poor hair growth
  • Pale or dry skin
  • Constipation
  • Lethargy or hyperactivity
  • Speech and other developmental delays
  • Distended belly

Considering the multitude of symptoms shared by both conditions, it’s practical for healthcare providers to test thyroid hormone levels in patients with Autism.

Proper diagnosis of both conditions is important for adequate management of symptoms.

Maternal thyroid problems and Autism in children

Many children with Autism have thyroid dysfunction. However, Autism develops early, and it’s impossible not to ask whether a mother’s health could contribute to the risk of developing this condition.

A study mentioned earlier in the article showed that fetal exposure to disorders affecting folate receptors could play a role in the pathology of Autism and the development of thyroid problems in children. That’s not the only piece of research to confirm that the mother’s health has an impact on autism risk in a child.

For example, Getahun et al. used records from 397,201 children who were delivered between 1991 and 2011 in order to analyze whether the mother’s hypothyroidism had any impact on autism risk in children.

Results showed that children of hypothyroid women had higher rates of Autism than kids of women who didn’t have this thyroid condition. The results occurred in women diagnosed before and during pregnancy.

Moreover, maternal hypothyroidism was associated with Autism in boys and girls as well. The problem wasn’t equally represented in children of different ethnic backgrounds. For instance, compared to white children, prenatal hypothyroidism was linked to higher autism risk in children of Hispanic mothers and women of other mixed-race ethnicities.

Scientists concluded the study confirming that maternal hypothyroidism is related to Autism in children. Management of hypothyroidism in mothers could decrease the risk of Autism in children[v].

Andersen et al. examined the association between maternal hyper- and hypothyroidism and the risk of Autism and ADHD in children. They analyzed data involving singletons born in Denmark in a period between 1991 and 2004. A total of 30,295 children were born to mothers with thyroid dysfunction.

Scientists found that maternal hyperthyroidism diagnosed and treated for the first time after the birth of the child increased the risk of ADHD, while hypothyroidism elevated the risk of Autism. However, no significant link was observed for maternal diagnosis and treatment of thyroid disorders before the birth of the child.

The study revealed that children born to mothers diagnosed and treated for the first time for thyroid dysfunction after their birth might have been exposed to abnormal levels of thyroid hormones in the womb. The untreated condition could boost the likelihood of specific neurodevelopmental conditions in the child[vi].

Roman et al. carried out an interesting study which showed that Autism is four times likelier when the mother’s thyroid is weakened. The research included over 4000 Dutch mothers and children, and it only contributes to the growing body of evidence of the link between Autism and lack of maternal thyroid hormone.

The study also revealed that autistic children had more pronounced symptoms if their mothers were severely deficient in T4 hormone. On the other hand, mild T4 deficiency was linked to an insignificant increase in symptoms of Autism. Scientists advise pregnant women, or ladies who are considering having children, having their doctor measure urine iodine and thyroid function beforehand[vii].

How is Autism treated?

Autism has no cure; there is no pill that would eliminate the condition entirely. The treatment is not the same for every patient.

The main objective of autism treatment is to maximize the child’s ability to function by managing symptoms and supporting development and learning. The doctor usually consults with other healthcare providers to create a treatment plan that would address the specific needs of every child.

Autism treatment options include:

  • Educational therapy
  • Behavior and communication therapy
  • Medications
  • Family therapy
  • Other therapies such as those to improve communication skills, improve movement and balance, etc.

Myths about Autism

MYTH: Autism is just a brain disorder.

FACT: A growing body of evidence confirms that children with Autism also have co-occurring disorders such as epilepsy, gastrointestinal problems, and others. As seen through this post, thyroid problems are also common in patients with Autism.

MYTH: Autism is caused by vaccination.

FACT: Lately we’re witnessing the rise of anti-vaccine parents who don’t want their kids to receive vaccine out of fears they might develop Autism. Autism is complicated, but no reliable study has confirmed a link between this condition and vaccines.

MYTH: Kids and adults with Autism don’t want to make friends.

FACT: Not true. The problem here is that kids, who grow up to be adults with Autism, don’t know how to socialize. Autism affects a person’s communication skills, socializing skills, and other aspects of life. To a person with Autism, it can be scary and overwhelming to socialize because it’s unknown territory for them.

MYTH: You can cure Autism with a specific diet.

FACT: Healthy and a well-balanced diet are important, particularly if your child has gastrointestinal problems in addition to Autism. However, Autism can’t be cured just by following a specific eating plan.

Conclusion

Prevalence of Autism has increased lately, but the condition still remains a mystery.

A growing body of evidence confirms that thyroid disorders are strongly associated with autism risk.

Healthcare providers should check thyroid levels in their pregnant patients.

Managing thyroid problems during pregnancy or before reduces the risk of Autism in children.

References

[i] Baio J, Christensen DL, Maenner MJ, et al. (2018). Prevalence of autism spectrum disorder among children aged eight years – Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2014. Morbidity and Mortality Weekly Report (MMWR), CDC, 67(6):1-23. Doi: 10.15585/mmwr.ss6706a1. Retrieved from: https://www.cdc.gov/mmwr/volumes/67/ss/ss6706a1.htm#contribAff

[ii] Autism facts and figures – prevalence, Autism Speaks. Retrieved from: https://www.autismspeaks.org/autism-facts-and-figures

[iii] Frye RE, Wynne R, Rose S, et al. (2017). Journal of Neuroendocrinology, 29(3). Doi: 10.1111/jne.12461. Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/28199771

[iv] Kellman R. (2011). The autism-thyroid connection. Prevention, vol. 15. Retrieved from: http://www.devdelay.org/documents/ThyroidautismarticleKellman.pdf

[v] Getahun D, Jacobsen SJ, Fassett MJ, et al. (2018). Association between maternal hypothyroidism and autism spectrum disorders in children. Pediatric Research, 83(3):580-588. Doi: 10.1038/pr.2017.308. Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/29244797

[vi] Andersen SL, Laurberg P, Wu CS, Olsen J. (2016). Attention deficit hyperactivity disorder and autism spectrum disorder in children born to mothers with thyroid dysfunction: a Danish nationwide cohort study. BJOG: an International Journal of Obstetrics and Gynaecology, 121(11):1365-1374. Doi: 10.1111/1471-0528.12681. Retrieved from: https://europepmc.org/abstract/med/24605987

[vii] Autism four times likelier when mother’s thyroid is weakened (2013). Science Daily. Retrieved from: https://www.sciencedaily.com/releases/2013/08/130813111730.htm

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