IL1B and Anxiety: Since it is well described that acutely elevated IL-1β induces anxiety [21], [22] and that the anhedonic and decreased neurogenesis effects of chronic unpredictable stress are mediated by IL-1 [23], it seems reasonable to argue for a role for endogenous IL-1 in inducing anxiety in normal animals and that decreased responsiveness to endogenous IL-1 drives decreased anxiety.