A Review of Depression in Patients after Thyroidectomy

Background: The association between a hypothyroid state and depression has been well documented in the literature, but few studies have measured rates of depression among patients after a thyroidectomy. Some observational data suggests that suboptimal thyroid replacement therapy may result in depression despite normal TSH levels, which has significant implications for monitoring patients after a thyroidectomy. This literature review will provide an overview of the existing research on depression in patients after a thyroidectomy. Method: The research was produced through a literature review using PubMed with search terms “Thyroidectomy” and “Depression.” Of the 191 search results, studies ranging from 1965-2017 published in English looking specifically at psychological depression among human subjects who had undergone a thyroidectomy were included. All studies or case reports of patients with a history of mood symptoms prior to the thyroidectomy were excluded, as were studies looking exclusively at perioperative depression and anxiety during periods of induced hypothyroidism. Eight articles were included with a total of 87 patients. Results: Three case reports were reviewed that documented psychotic depression and depression among hypothyroid patients after an average of 1.5 months without a thyroid. Among these cases, 100% had resolution of mood symptoms with thyroid replacement. In three other studies, investigators measured depression in the hypothyroid state versus euthyroid state in patients after a thyroidectomy. Investigators observed greater rates of depression and anxiety in hypothyroid patients. One case report documented a euthyroid MEN2A patient after a total thyroidectomy who presented with anxiety and depression found to be due to bilateral adrenal pheochromocytomas. One study looked at patients with thyroidectomy for Graves Disease and hypothyroidism secondary to Hashimoto’s Thyroiditis and found that adding carbimazole to levothyroxine (LT4) increased free triiodothyronine (FT3) and improved depression. Discussion: The existing literature on depression in patients after a thyroidectomy is limited. Case reports show psychotic depression and depression among patients with uncontrolled thyroid levels. No formal research has been done to study the prevalence of depression in euthyroid or subclinical hypothyroid patients after thyroidectomies over an extended time period. Given the observational data suggesting that current replacement therapy may not serve as a fully functional replacement for psychological well being, there may be a population suffering from mood symptoms after a total thyroidectomy. Further research is needed to determine whether physicians should monitor for mood symptoms after thyroidectomy and whether physicians should modify the current thyroid replacement regimen to maximize FT3.