Euthyroid sick syndrome in psychiatric inpatients

Numerous disorders are associated with euthyroid sick syndrome (ESS). This retrospective study examines the incidence and circumstances of ESS among 3188 psychiatric inpatients. There were 324 patients (10.2%) who met strictly defined criteria for ESS. Of these, 95 were hyperthyroxinemic (HT), 6 were hypothyroxinemic, 179 had mildly elevated thyroid-stimulating hormone (HTSH), and 47 had suppressed TSH. All were classified by DSM-III-R discharge diagnoses, encompassing five categories. X2 tests of significance of the 95 HT and 179 HTSH subjects revealed the following: 1) no relationship with age or gender; 2) the frequencies of HT and HTSH differed significantly (p< .05 and p< .01, respectively) across the five psychiatric categories; 3) HT frequency was highest in mood disorders (HT in mood versus others p< .02); and 4) HTSH frequency was highest in substance abuse (HTSH in substance abuse versus others p< .02). In conclusion, ESS is common in psychiatric inpatients, especially HT and HTSH; pathophysiologic mechanisms may vary according to psychiatric diagnosis.