Level of Thyroid-Stimulating Hormone (TSH) in Patients with Acute Schizophrenia, Unipolar Depression or Bipolar Disorder

The aim of this study is to investigate differences in thyroid-stimulating hormone (TSH) level in patients with acute schizophrenia, unipolar depression, bipolar depression and bipolar mania. Serum level of TSH was measured in 1,685 Caucasian patients (1,064 women, 63.1%; mean age 46.4). Mean serum TSH concentration was: schizophrenia (n = 769) 1.71 μIU/mL, unipolar depression (n = 651) 1.63 μIU/mL, bipolar disorder (n = 264) 1.86 μIU/mL, bipolar depression (n = 203) 2.00 μIU/mL, bipolar mania (n = 61) 1.38 μIU/mL (H = 11.58, p = 0.009). Depending on the normal range used, the overall rate of being above or below the normal range was 7.9-22.3% for schizophrenia, 13.9-26.0% for unipolar depression, 10.8-27.6% for bipolar disorder, 12.2-28.5% for bipolar depression, and 11.4-24.5% for bipolar mania. We have also found differences in TSH levels between the age groups (≤20, >20 years and ≤40, >40 years and ≤60 years and >60 years). TSH level was negatively correlated with age (r = -0.23, p < 0.001). Weak correlations with age have been found in the schizophrenia (r = -0.21, p < 0.001), unipolar depression (r = -0.23, p < 0.001), bipolar depression (r = -0.25, p = 0.002) and bipolar disorder (r = -0.21, p = 0.005) groups. Our results confirm that there may be a higher prevalence of thyroid dysfunctions in patients with mood disorders (both unipolar and bipolar) and that these two diagnostic groups differ in terms of direction and frequency of thyroid dysfunctions.