Hypothyroidism and Depression – Is There a Connection?

Will taking thyroid medication reduce or even eliminate depression symptoms? Do you still have depression even though you are on thyroid medication?

In this article, I will discuss the connection between hypothyroidism and depression, how thyroid medications can often help both conditions, and other causes of depression that you should consider.

Doctors are even taught to check thyroid lab tests in any patient that presents with new symptoms of depression. But how exactly are they connected? We aren't completely sure. ​However, we do know these connections:

​Hypothyroidism and depression share similar symptoms.

Depression symptoms resolve in some people that are treated for hypothyroidism.

Thyroid hormone increases serotonin levels in the brain.

Thyroid Releasing Hormone (TRH) is sensitive to serotonin. Low serotonin levels may stimulate TRH production, while high serotonin levels may lead to lower TRH production.


Basically, depression symptoms can sometimes (but not always) be due to hypothyroidism. So what is depression anyway:

Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day

Significant weight loss when not dieting or weight gain or decrease or increase in appetite nearly every day

Insomnia or hypersomnia nearly every day

Psychomotor agitation or retardation nearly every day (observable by others)

Fatigue or loss of energy nearly every day

Feelings of worthlessness or excessive or inappropriate guilt nearly every day

Diminished ability to think or concentrate, or indecisiveness, nearly every day

Recurrent thoughts of death, recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.

​Don't think of depression as a ​diagnosis. Instead, think of depression as a group of symptoms that may be caused by many different conditions. In other words, it is a side effect of one or more other problems. In order to properly treat the depression, the root cause must be identified and addressed.

Possible Causes of Depression:

Hormone Imbalances

Nutrient Deficiencies

Gut Dysfunction

Inflammatory States


Alcohol Use


Spiritual/Religious Issues

Hashimoto's and Depression:

Since up to 90% of hypothyroidism is caused by Hashimoto's Thyroiditis, it deserves discussion as well. As you might know, Hashimoto's is an autoimmune disorder that if left untreated will ​slowly and gradually destroy the thyroid gland, resulting in hypothyroidism.

Treatment of Depression with Thyroid Medication:

​Studies have shown that thyroid medication can be very effective in treating depression and depression symptoms. So why does thyroid hormone (particularly T3) help with depression?

These studies show that there is probably a connection between mood and thyroid function.

There may even be a subset of depressed patients that actually have ​hypothyroidism that has not been identified. There is also the possibility that some patients may have a genetic defect in one of the deiodinase enzymes that converts T4 to T3. This may result in a decreased level of T3 circulating in the brain.

I believe that it is good medicine to have a complete thyroid panel drawn on all patients that have symptoms of depression.

7 Steps to Consider if You Have Depression:

Get a Complete Thyroid Panel

Consider adding T3 medication to your current regimen

​Reduce your thyroid antibodies if you have Hashimoto's

​Identify and treat any nutrient deficiencies

Get good sleep

Manage your stress

Address any spiritual needs

Important Note: You may still ​need the use of an antidepressant (at least for a while), but finding the root causes of your depression and dealing with them directly will greatly improve​ your success in reducing or eliminating your depression symptoms. Many patients that have been diagnosed with depression also have thyroid issues, including hypothyroidism and Hashimoto's. In many cases, adding T3 thyroid medication can reduce depression symptoms, even when their TSH is normal.

If you have depression and hypothyroidism and are taking a T4 only thyroid medication, you may want to talk to your doctor about adding T3 or changing your thyroid medication to one that contains T3. It is important to get a complete thyroid panel to accurately assess your T3 levels and to check for the presence of Hashimoto's. As with most conditions, finding the root causes of your depression will allow you to directly address the issues that apply to you.

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