Thyroid function screening of psychiatric inpatient admissions: a worthwhile procedure?

A thyroid function screening programme of admissions to a general psychiatric service was established. Over a 22-week period 588 patients were admitted and thyroid function tests were performed on 336, a screening rate of 57.1%. Initial investigation showed that 21.3% had a total thyroxine outside the range 75-130 nmol/l. On further investigation only 9 patients (1 thyrotoxic, 8 hypothyroid) had confirmed thyroid disease. In 7 of the 9 patients the disease had been clinically suspected. Thus the screening programme identified only 2 unsuspected cases of thyroid dysfunction and we conclude that this level of detection does not warrant a formal screening programme.