The present invention describes the combination of a 5HT3-antagonist with pramipexole to reduce or eliminate the adverse effects associated with the use of pramipexole and to enable the use of high doses of pramipexole, useful for treating depressive disorders such as major depressive disorder.本發明描述5HT3拮抗劑與普拉克索之組合以減少或消除與普拉克索使用相關之不良作用且實現高劑量普拉克索使用,其適用於治療抑鬱症,諸如重度抑鬱症。