Hypothyroidism is common in the general population. Since symptoms and signs of hypothyroidism often mimic or overlap those of schizophrenia, they might be an under diagnosis of hypothyroidism in this population. Further, these patients may not be regularly seen by an Internist and may not be subject to routine thyroid profile testing. Treating occult thyroid abnormality is critical in these patients.

We studied the thyroid panel in 64 consecutive patients with schizophrenia seen in an Internist's office. Of these forty six (71.9%) were males and eighteen (28.1%) were females. The age ranged from 19 to 82. They were all on psychotropic medications. None were on lithium or thyroid supplementation. None of the patients exhibited clinical signs or symptoms of hypothyroidism. All of these patients underwent a routine thyroid profile testing.

Of these 64 patients, two (3.1%) patients were found to have elevated TSH. One had normal T3 and normal free T4, indicating subclinical hypothyroidism. The second patient had low T3 and low free T4 indicating overt hypothyroidism. Sixty two (96.9%) patients had an euthyroid profile.

In our study of 64 consecutive schizophrenic patients seen in an Internist's office, two were found to suffer from undiagnosed and untreated hypothyroidism. This limited study suggests that although not as common as suggested by the literature, undiagnosed and untreated hypothyroidism does exist in this population. All patients with schizophrenia should undergo a routine thyroid profile testing as part of a regular medical physical exam.