Mood Imbalances Part III:

The Thyroid-Depression Connection

By Sarah A LoBisco, ND

In last week’s edition of our health feedback, I discussed the Estrogen-Serotonin Connection in its relation to Mood disorders. In this three part series, I have covered the following underlying causes of mood disorders:

1. Neurotransmitter imbalances & their relation to nutrient deficiencies

2. Digestive disturbances & its resulting impact on brain function through the enteric nervous system

3. Estrogen’s affect on mood and its impact on serotonin

This week, I will discuss another hormonal connection to mood disorders- the thyroid gland.

Hormones and Mood: The Thyroid-Depression Connection

Thyroid disorders are among the most common hormonal disorders in the US. The impact of a thyroid is far-reaching, because it has such an important role in a variety of body regulatory processes. Thyroid hormone aids in carbohydrate, protein, & fat metabolism, vitamin utilization, mitochondrial function and ENERGY, digestive processes, muscle and nerve activity, blood flow, oxygen utilization, hormonal balance, overall metabolism, and more.

Due to the fact that thyroid hormones interplay with such a variety of biochemical messengers including neurotransmitters, low thyroid function (hypothyroidism) has many symptoms. These include: dry skin and hair, weight gain, physical weakness, muscle cramps, decreased libido, brain fog, menstrual irregularities, fatigue, and yellowed skin tone (thyroid hormone plays a role in the conversion of vitamin A in the liver to beta carotene). Specific emotional imbalances of hypothyroidism include depression-like symptoms, irritability, and anxiety.

As a naturopathic doctor and integrative health care professional, I am trained to look for the cause of thyroid imbalance. This means that two people diagnosed with the same disease label of hypothyroidism could have very different treatments depending on the root cause. Some common causes of thyroid deregulation that I see in my practice are hormonal imbalances, stress, immune conditions, and nutritional deficiencies.

Estrogen is one hormone that can seriously affect thyroid activity. Specifically, if estrogen can bind to thyroid binding globulin and down regulate thyroid hormonal output. Due to the estrogen-serotonin connection we discussed, it can have a major impact on mood.

Stress can affect the thyroid gland as well. Increased stress hormone output, such as cortisol from the adrenal glands, decreases thyroid conversion to its active form. This creates the symptoms of a low functioning thyroid gland. Furthermore, when one is low in thyroid hormone, the body will produce more adrenaline and catecholamines to make up for the energy it is not getting from thyroid hormone. These neurotransmitters have an excitatory effect on the brain and can cause one to feel irritable and anxious. It can also lead to adrenal fatigue with its resulting symptoms of fatigue and depression.

One way to help me determine the cause of hypothyroidism is serum lab tests. Many doctors only run a TSH test; however, this is not sufficient to measure thyroid hormone output. I always recommend my patients to request a fT3 and FT4 level from their conventional doctor as well. Furthermore, I like to obtain specific antibody tests to rule out autoimmune causes of thyroid imbalances. There are other tests I find helpful for assessing thyroid function which include: hormonal panels with a cortisol/DHEA ratio, insulin and glucose, nutritional assessments, lyme panel, intestinal permeability labs (especially for autoimmune issues), heavy metals, and stool analysis..

It is important to rule out the cause of thyroid dysfunction rather than to simply treat the symptoms, even with natural methods. This is why I suggest one consult with an integrative or functional medical practitioner to evaluate the cause of the problem and to establish an individualized treatment plan.

In health and wellness,

Dr. Sarah Lobisco, ND


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