Dos Santos-Júnior et al. (2016) identified a significant association between the number of CYP2D6*10 alleles and occurrence of obesity in children and adolescents receiving risperidone. All cross-sectional studies involved risperidone in either adults or children and adolescents except one (Mihara et al., 2000). Of note, Vanwong et al. (2014) and Sukasem et al. (2018) could have some partial sample overlap. This evidence concerns the gene CYP2D6 and obesity due to melanocortin 4 receptor deficiency.