Thyroid disease may contribute to mental illness, and thyroid dysfunction in psychiatric illness is common. However, the exact mechanism underlying the link between thyroid abnormalities and psychiatry illness is unclear, and the routine use of thyroid tests to assess psychiatric patients remains debatable. There are no specific guidelines about witch tests should be routinely done, however psychiatrists should be aware that thyroid test abnormalities do not always denote thyroid disease, because there are many factors that interfere with these tests at newly admitted psychiatric patients.

To review evidence about the clinical utility and cost-effectiveness of thyroid screening in psychiatric inpatients.

Searches were undertaken in PubMed and other relevant databases using keywords such as 'thyroid screening', 'psychiatric' and 'inpatients'.

Recent data suggests that clinical utility of thyroid testing in psychiatric patients is low, but in some subgroups of patients thyroid tests may be useful. In fact, there are few studies of cost-effectiveness of thyroid screening in psychiatric inpatients. Therefore clinicians have to pay attention to indications of request thyroid tests, to the moment of thyroid analyses and that transient nature of abnormal thyroid tests results may be a reflection of multitude of factors.

The diagnostic yield of thyroid testing in psychiatric patients is low, and recent studies do not fully support routine screening for thyroid dysfunction in psychiatry inpatients. However, the benefits of thyroid screening of newly admitted psychiatric patients should be evaluated in prospective studies.