The Relationship Between Anxiety and Thyroid Health

Both people with hypothyroidism and hyperthyroidism can experience anxiety.  Although one would suspect that the imbalance in thyroid hormone levels is the main reason for anxiety in those with thyroid and autoimmune thyroid conditions, there can be many other causes, and some people have multiple factors causing or contributing to their anxiety.  In this blog post I’ll discuss 4 main factors that can lead to anxiety.

Before discussing these four factors, it’s important to understand that there can be overlap, and sometimes we don’t know specifically what’s responsible for the person’s anxiety.  You’ll understand what I mean when reading through the four factors.  Of course if someone recently was diagnosed with Graves’ disease and they experienced anxiety shortly thereafter, there probably is a good chance that the elevated thyroid hormone levels were responsible for the anxiety, although this isn’t always the case.

A few days ago I sent an email letting my email subscribers know about an upcoming “Anxiety Summit”.  And while there will be a few dozen presenters discussing different topics, most of these topics fall under these four categories I’m going to discuss in this blog post.  With that being said, let’s take a look at the four main factors that can cause anxiety:

1. Thyroid hormone imbalances.  Most people reading this know that I see a lot of people with thyroid and autoimmune thyroid conditions.  And while I do have some patients with hypothyroidism and Hashimoto’s who experience anxiety, it is far more common in my hyperthyroid patients.  As far as the research that looks at the relationship between anxiety and thyroid health, one study looked at the psychiatric manifestations of Graves’ disease, including anxiety, and while resolving the hyperthyroidism associated with this condition may help, the authors also mentioned that a substantial number of patients have an altered mental state even after successful treatment of hyperthyroidism, which suggests that there might be other factors involved (1).  Another study looked at the relationship between anxiety and thyroid function in patients with panic disorder, and found that those with more severe panic attacks had a higher TSH, and that the severity of anxiety correlated negatively with free T4 levels (2).  In other words, the lower the free T4 levels, the greater the person’s anxiety.  Yet another study looked at the prevalence of anxiety and depressive symptoms among patients with hypothyroidism (3), and showed that psychiatric comorbidities such as depressive disorder, anxiety disorder, and disturbances in memory and learning are common in patients with hypothyroidism (3).

2. Inflammation.  Proinflammatory cytokines are associated with autoimmune conditions, such as Graves’ disease and Hashimoto’s, but the research also shows that they are present in generalized anxiety disorder (4).  Some of the research questions whether the inflammation can actually cause anxiety, but research suggests that proinflammatory cytokines can cause anxiety by modulating the metabolism of neurotransmitters, including dopamine and serotonin (5).  Another study showed that inflammation can affect anxiety-related brain regions including the amygdala, insula and anterior cingulate cortex, which may result from cytokine effects on monoamines and glutamate (6).

The problem is that a lot of things can cause inflammation.  This includes eating inflammatory foods, chronic stress, infections, poor oral health, environmental toxins, nutrient deficiencies, etc.  While taking certain supplements might help if someone has one or more nutrient deficiencies (i.e. vitamin D3, omega-3 fatty acids), many times this isn’t sufficient.  As a result, some detective work is usually needed to find the source of the inflammation.

3. Gut Dysbiosis.  In 2009 a journal article was written on the gut-brain axis (7), and since then there has been other articles that have discussed the connection between the influence of the gut microbiota on the brain, and vice versa.  The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans (8).  There are many factors that can affect the gut bacteria earlier in our lives, as well as in adulthood.  This includes but isn’t limited to the food we eat, stress, infections, gut disrupting medications (i.e. antibiotics, PPIs), and gut-disrupting chemicals (i.e. glyphosate).

Based on what I just said, it shouldn’t be surprising that certain infections such as parasites (9), along with having a Candida overgrowth (10) and small intestinal bacterial overgrowth (11) have been associated with anxiety and other mood disorders in the research.  While addressing these infections and/or overgrowth of yeast and bacteria can potentially resolve anxiety, it’s not always that simple.  For example, if someone has parasites and takes prescription drugs, this may get rid the parasites, but the antibiotics will also harm the good bacteria in the gut.  Also, while SIBO and a Candida overgrowth might cause anxiety, there is question whether this is related to inflammation and/or decreased nutrient absorption (10).

4. Nutrient deficiencies.  Certain nutrient deficiencies can cause anxiety.  Let’s take a look at some of them.

Thiamine. Thiamine (vitamin B1) has been used to treat patients with anxiety, with a dosage of 250 mg/day used (12).

Selenium.  Although I commonly recommend selenium to help support the immune system and increase glutathione production, a few intervention studies show that selenium can improve mood and diminishes anxiety (13) (14).

Magnesium.  Magnesium has many important roles in the body, and since it has a calming effect it shouldn’t be surprising that it also can play a role in helping some people with anxiety (15).

Vitamin D.  Research shows that a vitamin D deficiency can play a role in anxiety (16) (17) (18).  Keep in mind that vitamin D also has anti-inflammatory effects, and so this very well might be how it helps to reduce anxiety (by reducing inflammation).

Omega-3 fatty acids.  The research shows that omega-3 supplementation can lower anxiety (19) (20), although it might accomplish this by reducing inflammation.

Folate and SAMe.  Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme involved in the metabolism of folate, as it converts 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate.  Having polymorphisms (genetic variations) of MTHFR is common, and they can play a role in anxiety (21).  Both folate and SAMe play an important role in methylation, which in turn is important for the production of neurotransmitters.  As a result, in some people with an MTHFR polymorphism, supplementing with methylated folate and/or SAMe might help with anxiety, although it’s worth mentioning that sometimes this can also worsen a person’s anxiety.

Can Taking Herbs Help With Anxiety?

While addressing the factors discussed in this blog post should help with most cases of anxiety, some people choose to take herbs and other natural agents.  While it’s fine to take herbs on a temporary basis to help decrease anxiety, you also want to make sure to correct any underlying imbalances causing or contributing to the anxiety.  That being said, here are some of the herbs and other natural agents (other than those nutrients mentioned above) that can help to decrease anxiety:

Kava.  A few studies show that kava can help with generalized anxiety disorder (22) (23).

Ashwagandha.  Ashwagandha is an adaptogenic herb, and a few studies show that it can help to reduce stress and anxiety (24) (25).  Some reading this might be concerned that ashwagandha is a member of the nightshade family, and I discussed this in a past article entitled “Should Ashwaghanda Be Avoided in Those With Graves’ Disease and Hashimoto’s Thyroiditis?”.

Rhodiola.  Rhodiola rosea is another adaptogenic herb, and a few studies show evidence that rhodiola can help with anxiety symptoms (26) (27).

Gamma-aminobutyric acid (GABA).  GABA is the primary inhibitory neurotransmitter known to counterbalance the action of the excitatory neurotransmitter glutamate (28), and a few studies show that it can help with anxiety (28) (29).  It’s worth mentioning that phenibut is a form of GABA that has a phenyl group, which in turn allows it to easily pass through the blood-brain barrier (30).

Valerian root.  This herb is commonly used for the treatment of insomnia and anxiety, as it modulates the GABA-A receptors (31).

L-theanine.  One study suggests that chronic (8-week) L-theanine administration is safe and has multiple beneficial effects on depressive symptoms, anxiety, sleep disturbance and cognitive impairments in patients with major depressive disorder (32).  However, a more recent study did not support the efficacy of L-theanine in the treatment of anxiety symptoms in Generalized Anxiety Disorder (33).  I’ll add that I’ve had some patients experience a reduction of anxiety when taking L-theanine.

Lavender.  The two primary terpenoid constituents of lavender essential oil, linalool and linalyl acetate, may produce an anxiolytic effect in combination via inhibition of voltage-gated calcium channels, reduction of 5HT1A receptor activity, and increased parasympathetic tone (34).  A few studies show that Lavender oil can be an effective and well tolerated alternative to benzodiazepines for reducing generalized anxiety (34) (35).

What’s Your Experience With Anxiety?

For those reading this who have dealt with (or currently deal with) anxiety, I’d love to hear about your experience.  Do you know what caused your anxiety, and can you share what did you do to overcome it?  Perhaps you incorporated one or more of the factors I discussed in this blog post, or did you do something I didn’t mention?  If you’re currently experiencing anxiety what are you doing to help with it?  Thank you for sharing your experience with everyone!