TFF2 and Anxiety: SAD, one of the most common anxiety disorders with a life-time prevalence of 10–15%,2 is associated with a hyperactive fear circuit, most consistently the amygdala, during anxiety provocation22 and emotional perception.23 Given the role of the SP/NK1 system in stress and anxiety, and because treatment with NK1 receptor antagonists has shown promising initial results in SAD, including attenuation of stress-related amygdala activity,14 it could be hypothesized that this disorder is associated with altered NK1 receptor availability particularly in the amygdala.