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  • Writer's pictureDr. Melissa Dybala

Thyroid on Your Mind? How Thyroid Hormones Affect Brain Chemistry

Brain fog, depression, mood changes, memory problems: these symptoms have many causes. But did you know that thyroid hormone imbalance is often a big contributor to all of them?

The thyroid gland is a part of your hormonal system.  It sits in the front of the neck around the trachea and is responsible for a number of crucial functions from metabolism to cardiovascular health.

One reason thyroid health is tied so closely to brain health is that it receives signals from the pituitary gland, which is located in the brain. The pituitary gland, in turn, receives signals from the hypothalamus, which is also in the brain. The thyroid responds to signals from both the pituitary and hypothalamus glands by sending its own hormonal signals out to the entire body.

Secondly, there are thyroid receptors in every single cell in your body, any disruption in the thyroid’s signal or change in thyroid hormone levels can affect any part of the body – including the brain and other organ systems that affect brain health.

A third reason your thyroid can have such a profound effect on your brain is that it has multiple interactions with neurotransmitters or brain chemicals. Here are just a few:

Serotonin Decreased levels of serotonin are linked to depression. Low thyroid hormones lead to decreased serotonin levels and increased turnover of serotonin in your body. This means that not only can it cause low serotonin levels, but what you have is quickly eliminated. Serotonin helps release TSH from the pituitary, so if there is low serotonin, a vicious cycle begins: less TSH from the pituitary reduces thyroid hormone levels, which reduce serotonin levels. Serotonin issues are linked to mood changes, carb cravings, digestive issues, sleep issues, and more.

Acetylcholine This neurotransmitter helps you remember words, perform simple math, focus, and remember where you put your keys. If thyroid hormone is low, this may lead to low levels of acetylcholine.

GABA GABA is the most important inhibitory neurotransmitter and can become low in a developing brain or high in an adult brain when thyroid issues are present. Low and high levels of GABA can cause symptoms such as anxiety, depression, trouble sleeping, and addictive behavior.

Dopamine Levels of this excitatory neurotransmitter can decrease in those with low thyroid hormone. Dopamine helps to increase TSH, so low levels of dopamine can cause the same a vicious cycle as low levels of serotonin. Dopamine imbalance can cause a lack of motivation and energy, poor learning ability, memory trouble, as well as impulsive behaviors.

Working with a physician who understands the interactions between thyroid and neurotransmitters is important if you are experiencing brain or mood-related symptoms. A trained physician will help pinpoint whether your symptoms are a result of a thyroid imbalance vs. a non-thyroid related brain chemistry imbalance and get you on the right treatment plan.

Here at New Day Wellness Center, we use comprehensive lab tests for thyroid hormones including TSH, free T3, and free T4 for starters. We can also test your neurotransmitter levels via urine testing.

Both thyroid and brain health issues can be complicated territory, and it’s best to speak with your health care provider to find the best options and care for you.

One thing is clear, a healthy thyroid equals a healthier mind!


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