The symptoms of ADHD and thyroid disorder are similar. Some of the common overlapping symptoms are: brain fog, depression, difficulty staying focused, malaise or disinterest, poor memory and sleep disruptions. It’s important to determine if the symptoms are the result of an imbalance in brain chemicals (ADHD), a dysfunctional thyroid gland or both.
“There are two primary issues at play here,” says Kate Lieberman, a licensed clinical psychologist with expertise in psychological evaluation, including assessing for differential diagnoses. The two issues, Lieberman says, are: “thyroid dysfunction mimicking ADHD, and the possible relationship between thyroid dysfunction and the risk for developing ADHD.”
Thyroid hormone and thryoid disorders
Thyroid hormone is produced in the pituitary gland of the brain and sends signals to the thyroid gland, which is a small butterfly-shaped gland in the front of the neck. Thyroid hormone regulates the body’s metabolic rate-controlling heart, muscle and digestive function, brain development and bone maintenance, among other things.
Most importantly, thyroid hormones alter brain function. As Lieberman explains, disruptions to thyroid hormones can cause wide-ranging effects on cognition and behavior that can appear similar to symptoms of ADHD.
- In cases of hypothyroidism, an individual does not produce sufficient levels of thyroid hormone. Hypothyroidism can be caused by a variety of biological and environmental factors — such as poor hormone conversion, nutrient deficiency or environmental factors. “Symptoms can include fatigue and difficulty concentrating, mimicking the inattentive subtype of ADHD,” says Lieberman.
- With hyperthyroidism, an individual produces excessive levels of thyroid hormone. Hyperthyroidism can be caused by an autoimmune disease called Graves’ disease, Plummer’s disease and thyroiditis. “This condition,” says Lieberman, “results in hyperactivity, anxiety, tremors and difficulty concentrating, which can mimic symptoms of hyperactive ADHD — which includes restlessness — as well as inattentive ADHD.” Some of the overlapping symptoms between hyperthyroidism and ADHD are: anxiety, being easily distracted, excitability, hyperactivity, impulsivity, insomnia, irritability and lack of appetite.
Are thyroid dysfunction and ADHD linked?
For individuals with ADHD, a thyroid disorder can make symptoms worse. When the cell signals sent by the thyroid are atypical, the body is unable to function correctly and the brain receives mixed signals. But did the thyroid disorder cause the ADHD?
The evidence is mixed. The precise cause of ADHD remains unknown, but experts believe it has biological origins. “Research has repeatedly shown that children who were prenatally exposed to maternal thyroid dysfunction have a higher risk for developing ADHD,” says Lieberman. But that doesn’t mean that all ADHD is caused by thyroid issues.
It also remains unclear whether an individual is more likely to develop a thyroid disorder if he or she already has ADHD. Thyroid dysfunction and ADHD have similar symptoms — and they frequently coexist — but a causation link has not been proven.
Treatment for both?
Will treating thyroid dysfunction improve ADHD-like symptoms?
Yes and no. ADHD treatment often includes a combination of medication and cognitive-behavioral therapy.
Hypothyroidism is typically treated with thyroid hormone supplementation, while hyperthyroidism is treated with thyroid hormone-blocking medication. “Stabilization of thyroid hormones should result in a decrease of symptoms,” says Lieberman, “including those that mimic ADHD.” It is important to follow up with a primary care provider or endocrinologist to obtain periodic blood work to make sure thyroid levels are within a normal range.
For those with thyroid issues, treating ADHD without addressing thyroid dysfunction is not enough. Individuals who have both thyroid dysfunction and ADHD will not obtain symptom relief unless each condition is treated separately.