Background and aims: Many of hypothyroid patients that are under treatment with levothyroxine. In spite of normal blood level of thyroid hormones, they are suffering of depression symptoms that show it is necessary the normal level of TSH be detected specifically related to depression.
Methods: A cross-sectional study was conducted on 174 hypothyroid patients who referred to Endocrinology Clinic with levothyroxine with TSH levels of 0.5-5 MIU/L for more than one year. Laboratory surveys including TSH, T4 and T3 were performed. Beck depression questionnaire was completed for all patients by trained experts. Data were analyzed using MED CALC software and TSH cut-off values were determined based on depression by the Roc Curve test.
Results: 174 hypothyroid patients (Female: 116, Male: 58) with mean age 45.5±11.7 years old were entered to the study. According to Roc curve analysis, the optimal cut-off value of TSH based on depression estimated 2.5 MIU/L with 89.66% sensitivity.
Conclusion: The present study suggested that a TSH cut-off value for treatment of depression in hypothyroid patients should be based on depression, not just based on population studies. Based on the assessment of depression, our study concludes that a TSH cut-off value of 2.5 MIU/L is optimal. This cut point can provide the greatest effect in terms of depression improvement and quality of life for these patients.