Hashimoto's disease is an autoimmune form of thyroid disease, characterised by high levels of anti-thyroid peroxidase autoantibodies (anti-TPO). For many years it may or may not also result in a measurable effect on thyroid function, in terms of raising or lowering TSH (thyroid stimulating hormone) and T4/T3 thyroid hormones within the body.
Hashimoto's and Bipolar Coincidence
However, a recent study (1) showed a strikingly high rate of Hashimoto's disease in people with bipolar disorder, which far surpassed the normal (expected) rate of coincidence. The prevalence of anti-TPOs in those with bipolar disorder ran at 28%, compared to 3–18% in the control group (who were matched in all other measures, such as age, gender, etc, but suffered from different forms of psychiatric disorder). Thyroid failure was found to be present in 17% of bipolar patients, and was more prevalent among women than men. Even more recently, at the Sixth International Conference on Bipolar Disorder, research was presented showing that bipolar patients were twice as likely as healthy subjects to suffer from autoimmune thyroiditis.
Treating Bipolar and Thyroid Conditions Simultaneously
Not only have the two conditions been found to run side by side, but successful treatment for either seems to depend upon both being recognised. Two studies (2) have shown that people with bipolar depression are less likely to get better if they suffer from any form of hypothyroidism, even when undergoing extensive treatment.
The conclusion of psychiatrists and researchers working in this area is that thyroid function should be monitored very closely in those with bipolar disorder, for many reasons. The disorder is known to be associated with thyroid disfunction, and too much or too little thyroid hormone is known to lead to mood and energy changes, and because lithium treatment may cause thyroid hormone levels to lower, leading to hypothyroidism and increased mood changes.
Hashimoto's and Common Forms of Depression
Interestingly, people suffering from unipolar depression (the more common form of depression, normally treated with antidepressants) are also less likely to recover good mental health from depressive treatment alone, where any form of hypothyroidism is present (3). This means that if you happen to suffer from Hashimoto's or any form of hypothyroidism, it's likely that you would need to seek treatment for the thyroid condition before antidepressants could be expected to work.
Hashimoto's disease has often been linked to depression (4) and anxiety (5). A recent study by researchers at the Univerity of Cagliari, Italy, seems to suggest that individuals in the community with thyroid autoimmunity may be at high risk for mood and anxiety disorders. The link between autoimmune thyroid disease and unipolar depression was further confirmed in a 2004 study published in BMC Psychiatry. Compared to the control subjects, all the depressive subtypes here had significantly higher thyroid binding inhibitory immunoglobulins (TBIIs – a marker of Graves' disease), and atypical patients had significantly higher thyroid microsomal antibodies. Thyroid function markers – TSH, free triiodothyronine (FT3) and free thyroxine (FT4) – were normal, suggesting that unipolar depression might be characterised by a low-thyroid function syndrome.
What's the Connection Between Hashimoto's and Depression?
What's not clear, is which came first – the psychiatric condition or the autoimmune disease. It's thought that the psychiatric disorders and the autoimmune reaction may be rooted in the same deviancy in the immuno-endocrine system. And although scientists have yet to identify associated genes for bipolar disorder and autoimmune thyroiditis, the autoimmune thyroiditis (Hashimoto's) may be an endophenotype (a kind of biomarker) for bipolar disorder.
Read More
Controlling the Ups and Downs of Hashimoto's
Rebalancing the Thyroid Naturally
References:
- "High rate of autoimmune thyroiditis in bipolar disorder: lack of association with lithium exposure"; Kupka RW, Nolen WA, Post RM, McElroy SL, Altshuler LL, Denicoff KD, Frye MA, Keck PE Jr, Leverich GS, Rush AJ, Suppes T, Pollio C, Drexhage HA; Biol Psychiatry. 2002 Feb 15;51(4):305-11.
- Slower treatment response in bipolar depression predicted by lower pretreatment thyroid function; Cole DP, Thase ME, Mallinger AG, Soares JC, Luther JF, Kupfer DJ, Frank E.; Am J Psychiatry. 2002 Jan;159(1):116-21 and "Association Between Lower Serum Free T4 and Greater Mood Instability and Depression in Lithium-Maintained Bipolar Patients"; Mark A. Frye, M.D., Kirk D. Denicoff, M.D., Ann L. Bryan, B.A., Earlian E. Smith-Jackson, R.N., S. Omar Ali, B.S., David Luckenbaugh, M.A., Gabriele S. Leverich, M.S.W., and Robert M. Post, M.D.; Am J Psychiatry 156:1909-1914, December 1999
- 4 "Thyroid function in clinical subtypes of major depression"; Fountoulakis KN, Iacovides A, Grammaticos P:BMC Psychiatry 2004., 4(6).
- "Association between panic disorder, major depressive disorder and celiac disease. A possible role of thyroid autoimmunity"; Carta MG, Hardoy MC, Boi MF, Mariotti S, Carpiniello B, Usai P; Journal of Psychosomatic Research 2002, 53:789-793.
Sarah Tomley - Sarah is an editor and writer who has been working in the UK publishing industry for over 18 years. She has an honours degree in ...
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