Bipolar Disorder and the Thyroid: Is There a Connection?
How are bipolar disorder and thyroid dysfunctions linked?
In many cases, symptoms of hypothyroidism mimic the symptoms of bipolar depression, and symptoms of hyperthyroidism mimic the symptoms of bipolar mania. However, the connection doesn’t stop there. While disorders of the thyroid can affect your mood, mood disorders can also impair the function of the thyroid. Being diagnosed with one does not mean you have the other, but it’s important to get tested for thyroid disease if you are having any symptoms of a mental illness.
Bipolar disorder is characterized by two separate extremes in mood – mania and depression. A manic phase is defined by feelings of extreme euphoria and invincibility, while sometimes progressing into unprovoked anger and irrational decisions.
A depressed phase is defined by periods of intense self-loathing, sluggishness, and a loss of interest in most things. Though these symptoms can differ depending on which type of bipolar a patient is diagnosed with (for example, the hypomanic phase of bipolar II is a less intense form of mania), the overall symptoms follow these guidelines.
The symptoms of thyroid disorders are eerily similar.
Hypothyroidism is a disorder in which the thyroid produces fewer hormones than it is supposed to, while hyperthyroidism is when the thyroid produces more hormones than it is supposed to. Patients with hypothyroidism may feel weak, depressed, gain weight, and have difficulty sleeping. Those with hyperthyroidism may feel irritable, have a racing pulse, get jitters, have an increased libido, and have racing thoughts.
Since mania is in part caused by a chemical imbalance in the brain, hyperthyroidism makes sense as an underlying cause. The over-production of thyroid hormones leads to an increased amount of chemicals in the brain. The same is true for depression and hypothyroidism – as they are the opposite of mania and hyperthyroidism, respectively. Hypothyroidism tends to cause a decrease in the production of serotonin, which leads to a depressed mood.
If you believe you are having symptoms of bipolar disorder, you should first get your thyroid checked. Thyroid disease can be diagnosed through a blood test, while mental illnesses can only be diagnosed through the observation of signs and symptoms.
It’s especially important to get your thyroid tested before beginning any medications for bipolar, since some can negatively affect the thyroid. Even if you don’t have a thyroid disease and are having symptoms of bipolar, it’s still important to get your thyroid checked periodically (at least every 6-12 months) throughout treatment.
The most common treatment of bipolar is lithium – a mood stabilizer. For decades lithium has been known to have negative effects on the thyroid. The most common thyroid-related side effect is a goiter, which is the enlargement of the thyroid gland. It is estimated that approximately 50% of patients treated with lithium will develop a goiter within the first two years of treatment. Though slightly less common, 20-30% of patients taking lithium will develop hypothyroidism within the first two years, and the risk of developing it increases with age.
A major problem is that many people don’t assume that mental disorders and thyroid disorders are linked; many people with hypo or hyperthyroidism get treated for bipolar and wonder why their antidepressants and mood stabilizers aren’t having a positive effect on them. It is estimated that approximately 5.7 million US adults suffer from bipolar, while approximately 13 million suffer from thyroid disease. How many of those suffering from thyroid disease are misdiagnosed with a mental illness?
Many doctors rely on one lab test to determine whether or not patients have a healthy, functioning thyroid gland. However, most only test for the amount of TSH (thyroid stimulating hormone) in the bloodstream. Other thyroid hormone tests are available, such as Free T4, Free T3, Reverse T3, and TPO (thyroid antibodies). I don’t want to get too scientific, but each of these tests check for certain levels of hormones that all work together to create a healthy thyroid. Without testing for all of them, you can’t be sure whether or not you have a thyroid disorder. While many people don’t want to get tested for all of these due to the amount of blood tests it requires, it’s important to rule out all thyroid problems before beginning treatment for bipolar.
One treatment of thyroid disease has been known to help reduce the symptoms of mental illness. The most common treatment is Synthroid – a synthetic T4 hormone. However, treating patients with T3 hormone has been effective in treating bipolar symptoms. T3 has helped reduce symptoms of depression with fewer side effects than antidepressants. Many doctors automatically prescribe synthetic T4 hormone without getting to the underlying cause of the thyroid disorder. By testing for all hormones, as mentioned before, your doctor may find that a prescription for T3 hormone may fix both your thyroid problems and your bipolar symptoms better than Synthroid.
The Connection between Bipolar Disorder and the Thyroid
Though the correlation between bipolar disorder and thyroid disease is complicated, understanding that there is a connection between the two can help you better treat your symptoms. You may find that one thyroid medication may diminish symptoms of both bipolar and thyroid disease without a complicated mix of antidepressants, anti-convulsants, and mood stabilizers.
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