The effect of iatrogenic subclinical hyperthyroidism on anxiety, depression and quality of life in differentiated thyroid carcinoma.

Background/aim; Overt thyroidism is known to cause neuropsychiatric disorders but studies on subclinical hyperthyroidism (SCH) are limited. Subclinical hyperthyroidism induction by administering L-Thyroxine (LT4) is the standard treatment method in differentiated thyroid carcinoma (DTC) follow-up. Our aim was to investigate whether anxiety, depression and quality of life are affected in DTC patients followed-up with exogenous SCH. MATERIALS AND METHODS The patients were divided into exogenous SCH by LT4 -DTC (n= 127), euthyroid-DTC (n= 66) and exogenous euthyroid- benign thyroid nodule (BTN) who underwent thyroidectomy for benign thyroid pathology (n= 85) groups. RESULTS The rate of moderate/severe anxiety was significantly higher in SCH-DTC than euthyroid-BTN group (27.5%, n= 35 vs. 9.4%, n= 8) (p= 0.001). TSH levels and Beck anxiety inventory (BAI) scores were significantly negatively correlated (p= 0.009 r= -0.16). Free T4 and BAI were significantly positively correlated (p= 0.04 r= 0.4). The groups were similar in terms of depression severity (p= 0.15). Subclinical hyperthyroid- DTC group scored significantly lower than euthyroid-BTN group in all scales of SF-36 quality of life survey. CONCLUSION LT4-induced SCH, which is a part of traditional DTC treatment, can exacerbate the anxiety symptoms in patients and disrupt their quality of life, depending on the level of fT4.