Although previous studies have shown genetic associations between MDD and increased or decreased appetite and weight (68), as well as between MDD and increased weight gain and hypersomnia (69), to our knowledge, this is the first study to investigate the bidirectional association between BMI, MDD, CRP, and childhood trauma, indicating that once BMI is controlled for, only the association between MDD and childhood trauma remains. This evidence concerns the gene CRP and major depressive disorder.