Serum cortisol and insulin-like growth factor 1 levels in major depressive disorder and schizophrenia

The pathophysiology underlying major depressive disorder (MDD) and schizophrenia is related to endocrine system functions and includes changes in the blood levels of cortisol and insulin-like growth factor 1 (IGF-1). However, these hormones have not been investigated simultaneously in patients with MDD and schizophrenia. We investigated the differences in serum cortisol and IGF-1 levels among patients with MDD and schizophrenia and controls. We included 129 patients with MDD, 71 patients with schizophrenia, and 71 healthy volunteers. Blood tests were performed between 6:00 am and 11:00 am after fasting. Serum cortisol levels were significantly higher in patients with schizophrenia than in patients with MDD and controls. Serum cortisol levels were significantly higher in patients with MDD than in controls. Serum IGF-1 levels were higher in both patient groups than in controls, whereas there was no significant difference between patients with MDD and schizophrenia. Both cortisol and IGF-1 levels were positively correlated with the Hamilton Rating Scale for Depression score in patients with MDD, whereas cortisol level was positively correlated and IGF-1 level was negatively correlated with the Brief Psychiatric Rating Scale score in patients with schizophrenia. The differences in the level of these hormones suggest pathophysiological differences between these disorders.

Automated summary

The pathophysiology of major depressive disorder (MDD) and schizophrenia is related to changes in cortisol and insulin-like growth factor 1 (IGF-1) levels. This study investigated the differences in serum cortisol and IGF-1 levels between patients with MDD, schizophrenia, and healthy controls. The results showed that cortisol levels were higher in schizophrenia patients compared to MDD patients and controls, while MDD patients had higher cortisol levels compared to controls. Both patient groups had higher IGF-1 levels compared to controls, with no significant difference between MDD and schizophrenia patients. These findings suggest pathophysiological differences between these disorders.