<qa>  What is the name of the NK-1 receptor antagonist that exhibits central nervous system activity afterThe purpose of this study is to look at the safety and effectiveness of an investigational drug AV608 when used in subjects who have Social Anxiety Disorder. AV608 is an NK-1 receptor antagonist that exhibits central nervous system activity after oral administration. The study will compare AV608 to placebo a medically inactive substance to see if AV608 helps the symptoms of Social Anxiety Disorder. Eligible subjects will be assigned by chance to take either AV608 or placebo for 12 weeks. During the study, subjects will be asked about their overall health and mood and their Social Anxiety Disorder. 