<qa>  What is a new experimental drug that may assist in the reduction of uncontrolled episodes?Pseudobulbar Affect is a condition characterized by frequent episodes of laughing and crying out of proportion. Other terms used to describe this condition include emotional lability, emotionalism, emotion incontinence, emotional discontrol, excessive emotionalism and pathological laughing and crying. AVP-923 is a new experimental drug that may assist in the reduction of uncontrolled episodes. This study will test the safety and efficacy of AVP-923 in the treatment of MS patients suffering from pseudobulbar affect. 