Subclinical Hypothyroidism and Depression: Is There a Link?

摘要

Ontheotherhand,manypatientswithdepressionwho are screened for thyroid dysfunction have mildly elevated thyrotropin (TSH) and normal free thyroxine (T4) levels (mild or subclinical hypothyroidism). The patient and care provider may attribute the depressive symptoms to the mild thyroid disorder and initiate L-T4 therapy. Many of these patients are subsequently disappointed that their symptoms do not improve, which leads to overtreatment or use of nonstandard thyroid hormone preparations, with attendant risks. Corroborating this clinical impression, a recent report from the United Kingdom showed that L-T4 is being prescribed more frequently and for more mild degrees of hypothyroidism (2). This suggests that L-T4 is often prescribed for marginal reasons, which are commonly neuropsychiatric in nature. Despite this widespread use of L-T4, ;5% to 10% of hypothyroid patients on L-T4 replacement therapy have persistent affective symptoms despite nor- mal TSH levels [reviewed in Wiersinga (3)].