INS and major depressive disorder: We conducted two-sample MR using summary statistics for GLP1R plasma levels (n = 3,301) from the INTERVAL study, glycated hemoglobin (HbA1c) levels (n = 128,610) from the Meta-Analyses of Glucose and Insulin-related traits Consortium, and bipolar disorder (BD: 371 cases/360,823 controls) and major depressive disorder (MDD: 776 cases/360,418 controls) incidences from the UK Biobank.