Association between serum testosterone levels and the severity of negative symptoms in male patients with chronic schizophrenia

Objectives: Dysfunction of the hypothalamic-pituitary-gonadal axis may contribute to the pathophysiology of schizophrenia. Recent neuroendocrinological studies have suggested that gonadal sex hormones, including androgens and estrogen, play a significant role in the pathophysiology of schizophrenia. The purpose of this study was to determine any correlation between negative symptoms and the plasma levels of free testosterone, total testosterone, dehydroepiandrosterone sulfate, estradiol, and prolactin with consideration to depressive symptoms, extrapyramidal symptoms (EPS), and other factors including differences in age, diurnal variation of the serum hormone levels, and body fat composition. Methods: The subjects were 35 male inpatients with chronic schizophrenia aged 20-39 years. The patients' psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS). The Calgary Depression Scale for Schizophrenia (CDSS) and the Drug-induced EPS scale (DIEPSS) were also used to exclude the effects of depression or drug-induced movement disorders. Results: The PANSS negative scores had a significant inverse correlation with the serum total and free testosterone levels. The other hormone levels were not correlated with the PANSS negative scores. Moreover, a partial correlation analysis showed an inverse correlation between the PANSS negative subscores and the serum total and free testosterone levels after controlling for the DIEPSS and/or CDSS scores and age. Conclusions: This study indicates that total and free testosterone may play an important role in the severity of negative symptoms in male patients with schizophrenia.