Normal serum thyroxine values in patients with acute psychiatric illness.

The medical records of 278 consecutive patients with acute psychiatric illness admitted to a closed psychiatric unit after admission from the emergency room were reviewed. Serum thyroxine levels had been determined within 72 hours of admission in 106 patients (38 percent); in 74 of these patients (70 percent), the determination had been made within 24 hours. Ten patients (9 percent) were hypothyroxinemic, but further thyroid testing revealed that they were functionally euthyroid. Only one patient had hyperthyroxinemia, which was considered secondary to her postpartum state. The prevalence of hypothyroxinemia in the population studied is consistent with that in previous reports. However, the striking absence of hyperthyroxinemia in these patients is contrary to findings in several recent reports. Further prospective studies should clarify this issue.