Fig. 2

Bi-directional Mendelian randomization analysis between breakfast skipping and major depressive disorder. Using a P-value threshold of 5E-08, genetic predisposition to higher breakfast skipping frequency was associated with an increased major depressive disorder (MDD) (A). OR represented the risk change of MDD per unit increase in breakfast skipping. However, MDD was not linked with the susceptibility to breakfast skipping (B). Beta (β) coefficients represented the change in breakfast skipping per doubling odds of MDD. SNP, single nucleotide polymorphism; N, number