Effect of neuropeptide Y (NPY) treatment and dose on anxiety following symptom provocation in patients with posttraumatic stress disorder (PTSD). Figure displays observed values for anxiety measures before and immediately following a symptom provocation procedure (+32-minute time point) in subjects under NPY and placebo conditions (left column). Mean differences between NPY and placebo in change in symptom measure with associated SEs for each dose of NPY are also displayed (right column). In the case of summarized change scores depicted in the right column, the change in symptom severity (post minus baseline) is compared between NPY and placebo (PBO) as a difference score (NPY minus PBO). Therefore, larger numbers represent greater symptom severity, and negative difference scores indicate less anxiety symptoms under NPY relative to PBO. The dose-response effect was tested using an interaction term from a linear mixed model that adjusted for treatment order and baseline severity. (A) Beck Anxiety Inventory (BAI). (B) State-Trait Anxiety Inventory-State Form (STAI-State). (C) Impact of Events Scale-Revised (IES-R).