HRH3 and attention deficit-hyperactivity disorder: Antagonists and inverse agonists of the H3 receptor have been proposed as potential drugs for the treatment of attention-deficit hyperactivity disorders (ADHD), Alzheimer’s disease, obesity and others [18], [19], [20], [21], whereas H3R agonists are suggested for the treatment of asthma, migraine, and ischemic arrhythmias.