Thyroid axis functioning in psychotic patients during admission to mental hospital

Abstract

Thyroid dysfunction is related to mental disorders including psychoses such as schizophrenia. However, majority of patients with schizophrenia are euthyroid. The aim of this study was to evaluate peculiarities of thyroid axis functioning in euthyroid psychotic patients during admission to mental hospital in comparison to euthyroid donor controls.Blood samples were drawn from 84 psychotic patients consecutively admitted to the mental hospital. Blood samples from 100 donors served as control group. Twelve blood samples from patients group and 10 blood samples from the control group were excluded from the analyses due to increased serum concentrations of thyroid antibodies indicated autoimmune thyroiditis. Blood samples were assessed for Thyroid stimulating hormone (TSH) concentrations, for free thyroxine (FT4) concentrations, for free triiodothyronine (FT3) concentrations, and for sex hormone binding globulin (SHBG) concentrations using radio-immune assays.Psychotic patients compared to control group were older and had higher prevalence of women, so all comparisons were controlled for age, gender as well as for use of antipsychotic medications. Psychotic patients in comparison to control subjects had lower FT3 concentrations (p=0.041) and lower FT4 concentrations (p=0.014) with no differences in TSH concentrations and in SHBG concentrations. Differences in TSH concentrations were related to the age of the subjects (p=0.002) and differences in SHBG concentrations were related to the gender of the subjects p<0.001).Psychotic patients in comparison to control group of donors had lower FT3 concentrations and lower FT4 concentrations with no differences in TSH concentrations and in SHBG concentrations, suggesting that these differences in thyroid hormone concentrations did not affect thyroid hormone activity in tissues such as pituitary and liver.