Thyroid dysfunction in chronic schizophrenia within a state psychiatric hospital.

OBJECTIVES This study seeks to determine the prevalence and pattern of thyroid dysfunction in a group of adult psychiatric inpatients with chronic schizophrenia. We also hypothesize that raised thyroid hormones are associated with more severe psychopathology. METHODS Thyroid function tests were performed on 189 patients and the Brief Psychiatric Rating Scale (BPRS) was administered by a single rater on all patients. RESULTS There was a high prevalence of (36.4%) thyroid function test abnormalities but all patients except 1 were assessed to be clinically euthyroid. Free thyroxine (fT4) and triiodothyronine (fT3) were significantly higher in patients with mild (BPRS score, 10-20) and major syndrome (BPRS score, equal or above 21) compared to no syndrome (BPRS score, 0-9). No correlation was found between thyroid hormones and neuroleptic use. CONCLUSION Although thyroid function test abnormalities are common in patients with chronic schizophrenia, clinical thyroid illness was absent. This calls for caution in the use and interpretation of thyroid function tests in patients with chronic schizophrenia.