S100B and obesity due to melanocortin 4 receptor deficiency: Importantly, the effect sizes that BMI exerts on S100B blood levels in neuropsychiatrically healthy subjects (obesity compared to overweight: Cohen's d = 2.25; obesity compared to normal weight: Cohen's d = 2.90) are well within the range of effect sizes observed in schizophrenia (all studies: 2.02 ± 1.78; studies with drug-free patients: 1.94 ± 1.33) [2].