In summary, this individual PANSS-excitement subscale item analysis revealed that severe agitation, consisting of pronounced symptoms of excitement, hostility, tension, uncooperativeness, and poor impulse control, was related to either decreased or similar platelet MAO-B activity in large groups of smokers and non-smokers with PTSD, resulting in no association between platelet MAO-B activity and agitation. Here, MAOB is linked to post-traumatic stress disorder.