Objective: C-reactive protein (CRP) is the major acute-phase plasma protein. Studies show that patients with various mental disorders have elevated levels of CRP. The aim of the study was to determine differences in CRP serum level in patients with acute schizophrenia, unipolar depression, bipolar depression and bipolar mania. Method: Serum level of CRP was measured in 950 Caucasian inpatients (589 women, 62.0%; mean age 50.3 years). Results: Mean concentration of CRP in study groups was: schizophrenia (n = 485) 5.30 mg/l, unipolar depression (n = 319) 5.61 mg/l, bipolar disorder (n = 146) 4.65 mg/l, bipolar depression (n = 114) 3.82 mg/l and bipolar mania (n = 32) 7.36 mg/l. There was no difference for CRP levels between patients with schizophrenia, unipolar depression, bipolar depression and bipolar mania (P = 0.58). The overall rate of being above the high level of CRP (set at 3.0 mg/l) was 35.7% for schizophrenia, 38.6% for unipolar depression, 40.4% for bipolar disorder, 40.4% for bipolar depression and 40.6% for bipolar mania. There were no significant differences in the risk of having high level of CRP between the clinical groups. The rate of patients being above high level was higher in women. We also found that in whole study group CRP level was positively correlated with age (P = 0.002). Conclusions: Although there is no statistically significant difference in CRP serum level between patients with schizophrenia, unipolar depression, bipolar depression and bipolar mania, our results show that more than one-third (37.4%) of all subjects had CRP level > 3 mg/l, which is the cut-off point for high cardiovascular risk.

Aim: Brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) are neurotrophins—proteins that induce the survival, development, and function of neurons. Their role in the development of schizophrenia and mood disorders is widely studied. This study was aimed to determine whether depression affects levels of BDNF and NT-3 in patients with schizophrenia. Methods: Data for 53 Caucasian adult hospitalized patients with chronic paranoid schizophrenia was compared with 27 healthy subjects. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS) and positive, negative and general sub-scores, the Calgary Depression Scale for Schizophrenia (CDSS), the Hamilton Depression Rating Scale (HDRS), and the Clinical Global Impressions scale (CGI). Patients were defined as depressed (SHZ-DEP) with scores CDSS > 6 and HDRS > 7, otherwise they were included into the non-depressed group (SHZ-nonDEP). Results: In total, 17 patients (32.1%) with schizophrenia met criteria for depression. SHZ-DEP patients had higher scores in HDRS, CDSS, PANSS total, PANSS negative, PANSS general and CGI (p < 0.001 for all comparisons). There were no differences in BDNF or NT-3 levels between patients with schizophrenia and controls. BDNF levels were lower in SHZ-DEP compared to SHZ-nonDEP: 18.82 ± 5.95 versus 22.10 ± 5.31 ng/mL, p = 0.045. NT-3 levels were higher in SHZ-DEP compared to SHZ-nonDEP: 133.31 ± 222.19 versus 56.04 ± 201.28 pg/mL, p = 0.033. Conclusion: There were no differences in neurotrophin levels between patients with schizophrenia and controls. We found lower BDNF and higher NT-3 serum levels in depressed patients with schizophrenia.

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.