Thyroid and Bipolar Disorder
(Reviewed and minor revisions 12/2011)
Here are two reasons to care about thyroid:
1. There is a clear connection between the process of thyroid hormone regulation and bipolar disorder. The problem is, this connection is only just now beginning to become evident, and how the connection works is basically a mystery. Two studies recently showed a strikingly high rate of autoimmune-caused thyroid problems in people with bipolar disorder, far more than you would expect to find.Vonk, Kupka Thyroid problems are more common in the complex forms of bipolar disorder (mixed states and rapid cycling) than in classic bipolar manic patients.Chang Signs of thyroid auto-immunity are much more common in people with anxiety and depression, particularly the forms of anxiety which don’t easily fit into typical “anxiety disorder” labels.Carta
2. Two studies have shown that people with bipolar depression were less likely to get better if they had low thyroid levels, whereas the ones with higher levels responded pretty well.Cole, Frye . The same phenomenon was recently shown even in “unipolar” depression.Gitlin. These three studies are the basis for a treatment approach you could consider, particularly if depression is your main problem: gently pushing your thyroid status over toward the “hyperthyroid” end of normal, if you happen now to be toward the hypothyroid end of normal (the lab testing we use to place you on this spectrum is explained below). Update 4/2008: this approach, using just a little bit of the standard form of thyroid hormone — T4, explained below — was recently tested directly. The results were very positive, but it was a preliminary test with no control group.Lojko
Update 10/09: another research team recently concluded that “reduction in thyroid function can exacerbate bipolar symptoms even in euthyroid subjects.” Frye In other words, people who are in the normal range (“euthyroid”) can see their bipolar symptoms getting worse if their thyroid levels get low, even if that reduction leaves them still in the normal range.
(Finally, you should also know that some people think the standard lab testing for thyroid status does not do a good job of figuring out who’s “normal” and who’s not. In other words, they think that people who are not normal, who are low on thyroid hormone, will actually test “normal” using the standard measures. More on that controversy below).
Most doctors will not raise this option of adding thyroid unless you are clearly already low. It certainly isn’t the first thing to try for depression. But if you have tried several approaches and are considering what to do next; and if you have enough “bipolarity” to make antidepressants a concern, then it might be worth considering this approach, for this reason: as long as you and your doctor are careful, and don’t bump you right up into hyperthyroidism, there is no risk in trying this approach — just a series of blood tests, which a lot of people hate. And there is some risk if you end up hyperthyroid.
That is all supposed to sound pretty weak, as a justification for this approach. It is weak. But some people with bipolar depression need to know of every option they might try before turning to antidepressants, as explained in the essay entitled Antidepressants That Aren’t Antidepressants. If that’s not you, don’t go carrying this thyroid page to your doctor, she might scoff at you, as there is a long history of unsupported use of thyroid hormone and you don’t want to get branded as “one of those people”. Even so, the relationship of mood and thyroid is extremely complex, almost mysterious.
Let’s take a quick look at that complexity before turning back to why you might want to learn more about thyroid and bipolar disorder. There are reports linking the entire stress hormone system (here are some basics on stress and depression) to changes in thyroid function. This part is really complicated. The short version, translating from two amazing reviews of stress and mental health, is that stress hormones interfere with the production of thyroid hormone and with the conversion of thyroid hormone to its active form. Tsigos, Charmandari
It is also clear that people whose symptoms look the kinds of “bipolar disorder” explained on this website, have thyroid problems — and family members with thyroid problems — at a greater rate than would be expected. Is that because the thyroid problems somehow actually cause “bipolar”-like symptoms? Could it be that some of what looks like “bipolar” is actually a thyroid problem? There may be some such folks. In addition, there are clearly cases which seem to be “bipolar disorder” for sure, that get better with thyroid hormones as part of the treatment. In many of these cases it is clear that thyroid hormone was not enough, by itself, to make mood “normal”. So, for now I think it is safe to say that bipolar disorder has something to do with thyroid regulation in many cases, though not the majority; and that treating with thyroid alone is only rarely going to lead to full remission of symptoms (with a few notable exceptions…).
So, you need to know about thyroid and bipolar disorder for several reasons:
1. There is some relationship between the two, though poorly understood.
2. You need to make sure your thyroid is okay before you begin treatment for bipolar disorder, because
- if it’s not okay, you might not respond fully to treatment; and
- it’s usually pretty easy to get your thyroid hormone in the right place, which by itself could help your symptoms somewhat.
3. Thyroid hormone is sometimes used as a treatment for bipolar disorder, even if your thyroid is “normal” (by lab tests, anyway).
4. And finally, lithium commonly interferes with the thyroid system, so you’ll need to understand a bit about thyroid if you’re going to take lithium.