I once came across a patient who on the surface seemed to be suffering from severe psychiatric symptoms such as hearing voices, hallucinating, suicidal thoughts and severe anxiety. He also suffered from extreme heat intolerance, a racing heart, diarrhoea and insomnia…Many of these are signs of thyroid imbalance and I suggested he get it tested…sure enough he tested positive for hyperthyroidism (an overactive thyroid).

This was an uncommon case in my experience, but what is far more common is women who are tired, foggy-headed, forgetful, overweight, have dry hair and skin, constipated and also suffer from anxiety and depression….and for many of these women, they often have an underactive thyroid, or even Hashimoto’s disease, a condition in which the immune system is attacking the thyroid gland.

An even more common problem though, is many women who have the above symptoms, get their thyroid tested with their GP, and it comes back NORMAL…but normal is far from what they feel!

Does this mean their thyroid is functioning optimally? Is that all there is to their thyroid story? Not necessarily…I’ll explain why shortly, but first, it’s important to understand the link between thyroid imbalance and mental health.

The Connection Between Thyroid Imbalance and Mental Health

Firstly – a quick human biol lesson: the thyroid is a butterfly-shaped gland at the front of the neck that produces thyroid hormones that control metabolism and energy production in all cells of the body. Too much thyroid hormones can cause your body (and mind!) to be too “revved up” and too little can slow everything down too much, so it’s really important to have the optimal levels of thyroid hormones floating around!.

Your brain and nervous system is also very sensitive to thyroid hormones, and ever since the late 1800s, medicine has found a correlation between thryoid irregularies and mental health symptoms. In fact, these symptoms are often the first to appear when a thyroid is not functioning normally, and for many hypothyroid patients, the first practitioner they see is often a psychiatrist who may prescribe anti-depressants without checking thyroid function. ⁽¹⁾

Depression including bipolar depression; panic disorder; post-partum depression; and also social and generalised anxiety and even psychosis has been associated with thyroid disease, and thryoid dysfunction is a lot more common in women rather than men.

The Controversy Around Thyroid Testing

A good GP will hopefully test for thyroid function if a patient presents with depression. However, as mentioned above, I’ve come across many women whose test results come back normal but they have all the symptoms of hypothyroidism, so what’s going on?

Firstly, it’s important to understand how reference ranges work in medical testing. For example, the reference range for most labs for thyroid stimulating hormone (TSH) is 0.5 – 4,or sometimes even 5.5. That means if you have TSH above 4 you may have hypothyroidism (especially if you have low T4) ,and below 0.5  (with high T4) you may have hyperthyroidism. The controversial part is that the reference ranges are taken simply from whatever is reflected in the general population…and many of those people may have abnormal thryoid function! (In other words, the reference range hasn’t come from a sample population of people with optimally functioning thyroids, but a population consisting of a variety of people, many of whom may have poor thyroid function).  So, 0.5 to 4 is actually a very broad range, and several endocrinologists have suggested it be lowered to 3, but so far this hasn’t happened. (2)

Unfortunately, the guidelines for GPs state that TSH is an absolute indicator of whether or not a patient is living in a glandular hypothyroid state. So if a patients TSH level falls within that broad range…they’re told nothing is wrong with them. If it’s too high, they’re prescribed synthetic thyroid hormone.

Buuut….it’s not that simple…

The Naturopathic/Functional Medicine Approach

Naturopaths and functional medical practitioners take a different approach when doing thyroid tests – for one thing we’re not just looking for cut and dry numbers indicating whether there is “disease” or not. We’re looking for optimal thyroid function…if your test results are in the upper or lower thirds of the reference range, then you may not have overt thyroid disease that requires hormone replacement, but it doesn’t necessarily mean your thyroid is functioning optimally – and you may still be suffering from symptoms affecting your quality of life. Unfortunately, orthodox medicine doesn’t have much else to offer besides hormone replacement, which is another reason GPs don’t pay too much attention if the numbers are not outside the reference range, but there are nutritional and herbal treatments that can help improve sub-optimal thryroid functioning, and most importantly the symptoms that result.

Generally, GPs also won’t test for thyroid antibodies (markers showing if the immune system is attacking the thyroid gland, which is more serious than simply hormone imbalance) unless people have abnormal TSH results first. The problem with this, according to thyroid expert, author and pharmacist Isabella Wentz is:

“The TSH test can serve as an excellent method for picking up long-standing thryoid abnormalities, but unfortunately it does not always catch Hashimoto’s (an auto-immune thyroid disease) until the very late stages when a substantial amount of thyroid damage has occurred and the thyroid gland is no longer able to compensate. In the earlier stages of Hashimoto’s, a person’s TSH may fluctuate between the two extremes and at times even generate normal thyroid readings. You could have a normal TSH for years while experiencing unpleasant thyroid symptoms.”

The other difference in the way naturopath’s work with thyroid tests, is that we look for other patterns within the test results that gives us clues about the patients wellbeing. For example, if your TSH and T4 was normal, but your T3 was low, this tells us your body is not converting T4 (the storage form of thyroid hormone) to T3 (the active form), which could be due to inflammation, stress/adrenal imbalance, iodine excess or even gut dysbiosis. (And could manifest as chronic fatigue, lethargy, depression and similar symptoms to overt hypothyroidism). Low T4 could show zinc and selenium deficiency, an extremely important mineral that protects the thyroid gland from oxidative stress.

Another hormone we like to look at is reverse T3 – which is an inactive form of T3. High levels of T3 can indicate excess cortisol and potentially selenium deficiency.

So as you can see, getting a full thryoid panel done that looks at all the thryoid hormones including  reverse T3  as well as auto-immune markers can tell a lot about a patient’s state of health. But because of the guidelines around TSH, many GPs are restricted from being able to order the full panel and have it covered under Medicare/insurance. They’re also discouraged from testing “unnecessarily” so will not do the full panel unless TSH is abnormal.

Most naturopaths and functional medicine practitioners can order the full panel through specialised labs, but it does have to be paid for out-of-pocket. But if it means getting to the bottom of symptoms like depression, anxiety, fatigue and unexplained weight gain…it’s money well-spent.

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