I read your query and I understand your concern. I don t think Warfarin has any direct relation with your husband behaviour changes, it is not known to cause any such side effects. Perhaps in an indirect way, the fact that a previously healthy and active person has to take regular treatment for a long-term issue, with the necessity to getting regularly tested could contribute to altering his mood. Mood disorders are frequent in people suffering from chronic illnesses. That s just an assumption however. What matters regarding your question is that Warfarin doesn t affect his mood. If the problem persists perhaps you should try a psychiatric consult. I hope to have been of help.