HRH1 and obesity due to melanocortin 4 receptor deficiency: H1R antagonist properties have been identified as the main predictor for the development of antipsychotic-induced body weight gain/obesity side-effects (approximately Clozapine>Olanzapine>Risperidone>Haloperidol>Ziprasidone>Aripiprazole) [19], [20], [71], [72].