With a further delay of 2 weeks post-SPS before initiating treatment with IN-NPY, the proportion of mice displaying severe anxiety (as assessed by elevated plus maze) also increased from 17.5% to 57.1% (indicative of delayed onset/worsening progression of the PTSD-like induced phenotype) and only a higher dose of 300 μg was able to effectively reverse elevated anxiety, depressive-like, and hyperarousal behaviors [128]. This evidence concerns the gene NPY and post-traumatic stress disorder.