Hypothyroidism and Depression

Here's a few questions/answers on hypothyroidism I just answered today.

1) How prevalent, if known, is depression as a secondary problem to hypothyroidism?

While listed in the textbooks as a common symptom of hypothyroidism, clinically, most depression I see is not associated with hypothyroidism.

When I see a patient with depression one of the first things I do is run routine lab tests. Part of these tests includes a check of thyroid function (TSH,T3,T4). The vast majority of the time the thyroid functions are normal.

Interestingly enough, most patients I diagnose with hypothyroidism do not have any symptoms of depression at all and if they do have symptoms it is usually fatigue.

2) Can hypothyroidism first begin progressing very gradually, and then suddenly escalate?

Yes, it can. We know this by watching the TSH (Thyroid Stimulating Hormone), a hormone secreted by the front portion of the pituitary. A high TSH indicates an under active thyroid gland (hypothyroidism); while a low TSH indicates over activity of the thyroid (hyperthyroidism).

This is counterintuitive to most people, as one would think the opposite to be true. I.e. Low TSH=Hypothroidism; High TSH=Hyperthyroidism.

This is the case as it is the pituitary that is secreting the TSH, not the thyroid. If the thyroid is not secreting its hormones (T4, T3) effectively, the pituitary will know (because it ill see less of those hormones) and will increase its secretion of TSH. If the thyroid is secreting too much T4, T3, this will tell the pituitary to secrete less TSH.

The escalation of hypothyroidism will be seen biochemically as an increase in the TSH. The physician will then increase the amount of thyroid hormone they are giving the patient. The escalation can also be seen clinically, usually as an increase in fatigue, prompting the astute clinician to check the TSH with subsequent manipulation of the thyroid med dose.

3) Must a person take thyroxine lifelong, or can this disorder spontaneously remit?

When dealing with true hypothyroidism spontaneous remission will not occur. I make this statement definitively as hypothyroidism is a result of the thyroid gland losing its ability to make the thyroid hormones T4 and T3. These hormones are made via the modification of a substance within the thyroid known as thyroglobulin.

In the most common type of hypothyroidism known as Hashimoto’s Thyroiditis, the body begins to think the thyroglobulin is a foreign invader and begins to attack it. This is an autoimmune phenomenon as antibodies are created that then destroy the thyroglobulin. If there is no thyroglobulin, the body has no way to make the thyroid hormones. Thus, the only way to get the hormones would be via medication i.e. Thyroxine.

The medication will have to be taken for the person’s entire life.

4) Is the depression from hypo any different from a clinical depression that just comes for no reason, or the type that is triggered by chronic stress?

Yes, it is. Clinically, patients present more with fatigue complaints than with true clinical depression. When a patient presents with classic clinical depression, they are rarely hypothyroid. Even if a patient does have depression with concomitant hypothyroidism, treatment of the hypothyroidism will generally not eradicate the depression. Even though we learn in medical school and residency that we should always think of hypothyroidism when we diagnose depression, it is rarely the case that it is found.

Hope these answers help!

dr jim

Me and Mr Bones, fighting the fight against the medical establisment's dietary ignorance and we will not stop until everyone knows the truth.

Look for me and Mr. Bones March 6th on TV 55 (7:30 am-8:00 am)!