Depression and Thyroid Health
Published September 23rd 2013
It’s not uncommon for people with a thyroid or autoimmune thyroid condition to suffer from depression. Although this is more common in people with hypothyroidism and Hashimoto’s Thyroiditis, people with hyperthyroidism and Graves’ Disease can also suffer from depression. And while there are ways to treat depression naturally, one really does need to be careful when dealing with someone who has moderate to severe depression.
But what causes clinical depression? Just as is the case with someone who has a thyroid or autoimmune thyroid condition, it seems that depression is caused by both genetic and environmental factors (1). Most genetic studies of major depressive disorder have considered the impact of functional polymorphisms relevant to monoaminergic neurotransmission (2). A genetic polymorphism involves variants of a specific DNA sequence. While there is a genetic component to depression in many people, lifestyle and environmental factors also can play a big role in the onset of this condition.
Low depression has been associated with decreased serotonin levels for years. However, the relationship between serotonin and clinical depression is still controversial. Recent evidence suggests that depression is due to communication problems between the brain cells (3). If this proves to be true then this might change the conventional treatment methods, which involve selective serotonin-reuptake inhibitors (SSRIs), tricyclic antidepressants, monoamine oxidase inhibitors, and other drugs.
Can Having Depression Trigger An Autoimmune Thyroid Condition?
The secretion and production of proinflammatory cytokines are increased in people who suffer from depression (4). Because proinflammatory cytokines can potentially trigger an autoimmune response, can having depression lead to the development of a condition such as Graves’ Disease or Hashimoto’s Thyroiditis? Although this might be possible, there are no clinical studies I’m aware of which demonstrate a link between depression and autoimmunity.
With that being said, there is a correlation between stress and thyroid autoimmunity. (5) (6) And it’s safe to conclude that many people with depression are stressed out. But of course the same thing can be said with other conditions, as stress is a factor for many people.
Depression In People With Hypothyroidism and Hyperthyroidism
There have been numerous studies on depression in people with thyroid conditions. One study looked to determine the prevalence and incidence of hypothyroidism and hyperthyroidism in patients with major depressive disorder (7). The study concluded that patients with major depressive disorder had a higher prevalence and a higher incidence of hypothyroidism or hyperthyroidism than the general public.
Depression and Hypothyroidism
Depression seems to be more common in people with hypothyroidism. The authors of one study concluded that depressed patients should be screened for hypothyroidism, and in these patients, depression may be more responsive to a replacement regimen that includes T3 rather than T4 alone (8).
Another study looked to see if people with subclinical hypothyroidism were more likely to suffer from depression (9). Subclinical hypothyroidism usually involves an elevated TSH, but normal thyroid hormone levels. The study concluded that depression was more common in those people who met the criteria for subclinical hypothyroidism.
Another study looked to evaluate whether thyroid hormonal changes during menopause may affect the development and the course of major depressive disorder (10). The authors of the study concluded that thyroid hormones may have an impact on the severity and efficacy of antidepressant treatment, but also mentioned that further studies are required to look at the role of thyroid hormones in depression after menopause.
Depression and Hyperthyroidism
Even though depression is more common in people with hypothyroidism, some people with hyperthyroidism and Graves’ Disease also suffer from depression. In fact, hyperthyroidism can be associated with various psychiatric symptoms, such as emotional lability, anxiety, restlessness, and rarely frank psychosis (11). In fact, in one study involving a female patient with depressive symptoms who had hyperthyroidism, a thyroidectomy helped to resolve the problem, as the person was able to stop taking antipsychotic medication (11).
The purpose of bringing up this case study isn’t to suggest that those people with hyperthyroid conditions who also suffer from depression should receive thyroid surgery, but is to demonstrate that normalizing the thyroid hormone levels could help with depression. Of course I prefer to take a natural approach and have the patient avoid surgery whenever possible.
However, while correcting hyperthyroidism might help with depression, this might not always be the case. One study looked at Graves’ Disease patients who were treated with antithyroid medication, and concluded that depressive personality during treatment reflects the effect of emotional stress more than that of thyrotoxicosis and that it aggravates hyperthyroidism (12). In this case they said that antipsychiatric drugs and/or psychotherapy can be useful for helping people with hyperthyroidism.
Are Natural Treatment Methods Effective For Depression?
Many natural healthcare professionals are understandably cautious when it comes to recommending a natural treatment protocol to someone who has moderate to severe depression. While there are things that can be done to help someone naturally, taking someone off the medication has its risks, and so this is something I will never do. However, if someone with hypothyroidism or hyperthyroidism suffers from depression, then of course I will recommend trying to restore their thyroid health, which in turn very well might help them overcome the depression.
Let’s take a look at some supplements and herbs which can benefit some people who suffer from depression.
St. John’s Wort. Just about everyone is familiar with St. John’s Wort and its role in depression. But does the research support this? Well, one study looked at the effects of St. John’s Wort in mild to moderate depression (13). Hyperforin is a phytochemical present in St. John’s Wort, and this study showed that the therapeutic effect of St. John’s Wort in mild to moderate depression depends on its hyperforin content. An extract using 5% hyperforin was more effective than an extract using 0.5% hyperforin. Another study which looked to determine the efficacy of St. John’s Wort in the treatment of mild to moderate depression concluded that practitioners may find St. John’s Wort a viable complimentary treatment alternative to traditional medical treatment (14).
However, the effectiveness of St. John’s Wort in helping with major depression is controversial. One study involving 200 participants concluded that St. John’s Wort was not effective for the treatment of major depression (15). However, a more recent study concluded that St. John’s Wort is similarly effective as standard antidepressants (16). I personally would be very cautious about using St. John’s Wort as a substitute for medication in severe depression.
Vitamin D. Numerous studies have shown that Vitamin D is important in preventing depression. And most people I consult with are deficient in vitamin D. One study shows that effective detection and treatment of inadequate vitamin D levels in persons with depression and other mental disorders may be an easy and cost-effective therapy (17). Another study looked at the relationship between serum vitamin D levels and depression (18), and concluded that low vitamin D levels are associated with depressive symptoms, especially in persons with a history of depression. But does supplementation with Vitamin D3 help with depression? Not necessarily, as one study showed that low levels of serum vitamin D are associated with depressive symptoms, but no effect was found with vitamin D supplementation (19). However, another study showed that supplementation with high doses of vitamin D may help with the symptoms of depression (20).
5-HTP. 5-hydroxytryptophan (5-HTP) is the precursor of serotonin. And 5-HTP is able to cross the blood-brain barrier (21). There is evidence that 5-HTP can help with depression, and relatively few adverse effects are associated with its use in the treatment of depressed patients (22) (23). However, in some patients with depression 5-HTP might be contraindicated. Plus, long term use of 5-HTP can deplete the catecholamines dopamine, norepinephrine, and epinephrine (21). And when dopamine depletion is great enough, 5-HTP will no longer function (21).
Inositol. CSF levels of inositol have been reported to be lower than normal in depressed subjects (24). And numerous studies have shown that inositol might be effective in helping with depression. (24) (25) (26) Larger doses of inositol were used in these studies, as the people in one study took 6 grams of inositol per day, and the other two studies involved people taking 12 grams of inositol per day.
Omega 3 Fatty Acids. I commonly recommend omega-3 fatty acids in the form of fish oils to help with the inflammatory component of thyroid and autoimmune thyroid conditions. But there is evidence that omega-3 fatty acids can also help with depression. In one series of studies omega-3 fatty acids were shown to be more effective than placebo for depression in both adults and children (27). Another study showed that omega-3 fatty acids helped to ameliorate depressive symptoms in depressed elderly female patients (28). Another study looked to see if omega-3 supplementation can reduce depressive symptoms in patients experiencing a major depressive episode (29), and concluded that there was a trend toward superiority of omega-3 supplementation in reducing depressive symptoms.
There are other nutrients which can also potentially help with depression. Some of the other ones which may help include L-tryptophan, Vitamin B12, Folate, Vitamin B6, magnesium, iron, and Vitamin C. Keep in mind that certain nutrients are important for the synthesis of the neurotransmitters, such as serotonin and norepinephrine. As a result, a deficiency in one or more of these can result in depression.
In summary, depression is common in people with thyroid and autoimmune thyroid conditions. Although depression does seem to be more common in people with hypothyroid conditions, many people with hyperthyroidism also experience depression. The conventional medical treatment usually consists of selective serotonin-reuptake inhibitors (SSRIs), tricyclic antidepressants, monoamine oxidase inhibitors, and other drugs. But certain nutrients and herbs can also potentially help some people with depression.