Amantadine in depressive patients with Borna disease virus (BDV) infection: an open trial

Objective: Originally introduced into pharmacotherapy as an antiviral compo und, amantadine was shown to also have multiple pharmacological effects on the central nervous system. In addition, only a few studies reported on cer tain antidepressive properties of amantadine. This effect was highlighted b y the discovery of its antiviral effect on Borna disease virus (BDV), which is hypothesized to be an etiopathogenetic factor to subtypes of affective disorders. Therefore, the therapeutical use of amantadine in BDV-infected d epressive patients was investigated. Methods: In this open trial, amantadine was added to antidepressive and/or mood-stabilizing compounds treating BDV-infected depressed patients (n = 25 ) with bipolar or major depressive disorders. Amantadine was given twice a day (100-300 mg/day) for a mean of 11 weeks. Antidepressive treatment respo nse was measured on the Hamilton rating scale for depression (HAM-D) and/or with an operationalized diagnostic criteria system (OPCRIT; version 3.31). Virological response was measured by expression of BDV infection parameter s in blood samples. Results: The overall response rate of the amantadine augmentation in the BD V-infected patients with regard to depressive symptoms was 68% after a mean of 2.9 weeks of treatment. Bipolar I patients improved faster and did not show any following hypomania. In addition, the decrease of depression tende d to correspond with the decrease in viral activity. Conclusion: Amantadine appears to show a remarkable antidepressive efficacy in BDV-infected depressive patients. The antidepressive effect in this ope n trial appeared to be comparable to standard antidepressives, possibly bei ng a result of its antiviral effect against BDV as a potentially relevant e tiopathogenetic factor in these disorders.