We all know that low thyroid hormones can lead to feelings of sadness and anxiousness. One of the most common causes of low thyroid hormones is an auto-immune condition called Hashimoto’s thyroiditis. With this condition, your body attacks and injures your thyroid gland which contributes to reduced thyroid function.

One of the hallmarks of this conditions is elevated thyroid antibodies—anti-thyroperoxidase and anti-thyroglobulin antibodies. For the longest time, these were viewed as markers of Hashimoto’s thyroiditis but not much attention was paid to them in the doctor’s office.

Now, more research is showing that high thyroid antibodies may be playing a role in mental health regardless of thyroid hormone levels. In other words, we should be paying attention to antibodies in addition to hormone levels.

A 2024 meta-analysis by Wang et al. examined 11 studies on this topic. Patients had normal thyroid hormone levels but high thyroid antibodies, a state known as euthyroid Hashimoto’s thyroiditis. Most patients were from Europe and China and there were over 1300 patients with depression and over 1000 patients with anxiety across all of these studies.

Those with normal thyroid hormones but elevated thyroid antibodies had 2.5 times higher odds of having an anxiety disorder. They were also more likely to experience depression symptoms based on validated questionnaires.

But why might the thyroid antibodies themselves impact mood? What could they be doing to the body? Researchers think that thyroid antibodies may negatively impact the nervous system. They may impact nerve cells or brain function—scientists aren’t completely sure yet.

It’s important to note that some studies show no link between thyroid antibodies and mental health. That being said, this assessment of multiple studies provides illuminating insight into the potential link between thyroid antibodies and mental health. In my practice, I regularly test thyroid antibodies for my patients with anxiety and depression because there are natural ways to address this issue. I wrote another article on this topic a couple years ago, before this new paper came out. You can read it HERE.

If you’re in Ontario and you need help uncovering the underlying factors impacting your mental health, book a free 15 minute phone consultation and we can chat about it.