As had been shown recently, the intravenous administration of irisin in spontaneously hypertensive rats, a model of ADHD (Botanas et al., 2016), resulted in normalization of blood pressure (Huo et al., 2020) that, together with changes in the paraventricular nucleus, suggest changes in ACHT-vasopressin system. The gene discussed is FNDC5; the disease is attention deficit-hyperactivity disorder.