Altered serum levels of matrix metalloproteinase-2,-9 in response to electroconvulsive therapy for mood disorders

Abstract

Background: Inflammatory processes could underlie mood disorders. Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMP) are inflammation-related molecules. The current study sought an association between mood disorders and systemic levels of MMPs and TIMPs. Methods: Serum was obtained from patients with mood disorders (n = 21) and patients with schizophrenia (n = 13) scheduled to undergo electroconvulsive therapy. Serum was also obtained from healthy controls (n = 40). Clinical symptoms were assessed by the Hamilton Rating Score for Depression and the Brief Psychiatric Rating Scale. Serum levels of MMPs and TIMPs were quantified by ELISA. Results: The serum levels of MMP-2 in mood disorder patients, but not in schizophrenia patients, prior to the first electroconvulsive therapy session (baseline) was significantly lower than that of healthy controls. At baseline, levels of MMP-9 and TIMP-2,-1 were not different between patients with mood disorder and schizophrenia and healthy controls. After a course of electroconvulsive therapy, MMP-2 levels were significantly increased in mood disorder patients, but MMP-9 levels were significantly decreased in both mood disorder and schizophrenia patients. In mood disorder patients, there was a significant negative correlation between depressive symptoms and serum levels of MMP-2 and a positive correlation between depressive symptoms and MMP-9. In addition, alterations of serum levels of MMP-2 and MMP-9 were significantly correlated each other and were associated with certain depressive symptoms. Conclusion: A change in inflammatory homeostasis, as indicated by MMP-2 and MMP-9, could be related to mood disorders, and these markers appear to be sensitive to electroconvulsive therapy.