May masquerade as a psychiatric illness. Underactive thyroid, called hypothyroid, may present symptoms similar to depression; sad mood, low energy, joint and muscle pain, and fatigue. Hypothyroidism often has additional symptoms not seen in depression, such as weight gain despite no change in food intake (due to slowed metabolism), dry skin, constipation, cold intolerance, and excessive menstrual bleeding. It is most often caused by an autoimmune disease called Hashimoto’s disease, but has several other causes also. Treatment is often via replacement of thyroid hormone. Over active thyroid is called Hyperthyroidism, and may present with anxiety or in severe cases, manic like behavior. Additional symptoms can include irritability, sense of panic due to episodic increases in pulse, and difficulty sleeping. Other symptoms unrelated to mood disorders that can present in hyperthyroidism include but are not limited to heat intolerance, weight loss despite (often eating more than usual), hand tremors, muscle weakness, sweating more, and lighter menstrual flow. There are multiple causes for hyperthyroidism, most commonly the autoimmune disease ‘Grave’s disease.’
Thyroiditis is inflammation or swelling of the thyroid, and can be seen in postpartum thyroiditis, which affects up to 10% of women in the months after giving birth. Like the thyroid diseases above, an autoimmune process likely causes postpartum thyroiditis where the body attacks the thyroid. However, unlike Hashimoto’s and graves diseases, postpartum thyroiditis is often transient and self-limited. In the first 1-4 months after delivery, the thyroid damaged by the body’s altered immune system that attacks itself, leaks thyroid hormone. In the ensuing period, often 4-8 months after delivery, the thyroid has leaked out all its hormones and is now nearly empty, so symptoms of hypothyroidism may be present at this stage. The thyroid reconstitutes and heals often by 12 -18 months postpartum. However, once postpartum thyroiditis is identified, it is often truncated via medication.
Not all women experience both phases of postpartum thyroiditis. Women at increased risk for postpartum thyroiditis include those who have had it following previous deliveries, women with pre-existing thyroid disease, either for themselves or in closely related family members, and those with other autoimmune diseases.
It is imperative and can be highly informative either during or after a pregnancy to have a full thyroid panel drawn. This includes TSH (thyroid stimulating hormone), free T4 and T3 (thyroid hormones), and thyroid antibodies. TSH tells the thyroid to make thyroid hormone, and elevations or reductions in TSH as compared to thyroid hormone levels can be informative about any possible thyroid abnormality present.
Normal TSH, free T4 and T3 but elevated autoantibodies may indicate a heightened risk for a postpartum thyroiditis and postpartum depression, and warrants further evaluation by a specialist.
Undiagnosed and/or untreated hyper- or hypo-thyroid may make it more difficult to conceive, and untreated, both may negatively impact a pregnancy in terms of both maternal and fetal health. Untreated thyroid illness can cause mood disturbances during and after pregnancy as well as at any time in a woman’s life, as reviewed above. As such, it is always important to evaluate the health of the thyroid and treat any present abnormality in order to ensure overall physical health and mood stability.