Interrelationships between sex hormones, brain-derived neurotrophic factor, and cognitive impairment in male patients with schizophrenia and receiving chronic antipsychotic treatment

Background: Complex interactive effects between brain derived neurotrophic factor (BDNF) and sex hormones are known to be involved to the pathogenesis of schizophrenia (SCZ). However, the impact of these interrelationships between BDNF and sex hormones on cognitive function and clinical manifestations in chronic antipsychotic-treated male (CATM) SCZ patients have yet to be investigated. We investigated interrelationships between sex hormones, BDNF, clinical symptoms, and cognitive function, in the CATM patients with SCZ. Methods: : Serum concentrations of follicular-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), progesterone (P), testosterone (T), and prolactin (PRL) were compared between a group of 120 CATM patients with SCZ and a group of 120 healthy controls. Schizophrenia symptoms were measured by the Positive and Negative Syndrome Scale, cognition by the neuropsychological tests. The levels of BDNF and sex hormones were determined by enzyme linked immunosorbent assay (ELISA). Results: : Levels of T, PRL and LH were significantly higher in the patient group than in the healthy controls while E2 levels were significantly lower. Analysis also identified positive correlations between E2 levels and BDNF levels, and BDNF levels and the digital cancellation time, in the whole sample. we found significant correlations between PRL levels and negative symptoms score in CATM patients with SCZ. Conclusions: : This study provides the first comprehensive assessment of elevated levels of LH, PRL, and T, as well as reduced levels of E2, in CATM group when compared with controls. Another exciting finding in this study is that E2 levels and BDNF levels, along with BDNF levels and the DCT, were significantly and positively correlated in the combined subjects.