Objective: The relationship between thyroid dysfunction and depression remains controversial. Aim of this study was to evaluate the clinical usefulness of the routinely requested thyroid function tests for the psychiatric out patients admitted with the diagnosis of depression.

Materials and Methods: The thyroid function tests (FT4, FT3, TSH) of the 1120 adult outpatents were reviewed. The patients were followed-up for the clinical compliance of their thyroid dysfunctions in the following days.

Results: TSH, FT3 and FT4 values of the 85.4% patients were found as in normal range, and 10.6% of patients' tests were out of the reference range.

Conclusion: The clinical usefulness of the thyroid screening in patients admitted with the diagnosis of depression has to be revisited. We conclude that, if needed, TSH test should be requested primarily.