a DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) major depressive disorder diagnosis. For FINRISK we excluded 820 (26%) current smokers and 775 (29%) former smokers who either (i) reported having a diagnosis of cancer of cardiovascular disease (angina pectoris, heart failure, asthma, pulmonary emphysema, or bronchitis), (ii) reported being on a disability pension, or (iii) reported self-rated health as ‘poor’ or ‘very poor’. Further, we adjusted the analyses for alcohol use, a known confounder, i.e. factor associated with both NMR and smoking behavior (grams of ethanol consumed during the last week in FINRISK, and grams of ethanol consumed on average per week in NAG-FIN). We also ran additional wGRS analyses with an rs56113850*rs113288603 interaction term included as a covariate, to account for the detected interplay between these two SNPs. As four independent SNPs emerged in the FINRISK2007 GWAS sample, and the main wGRS sample was derived from FINRISK cohorts, we report results for the 4-SNP wGRS; however, the 3-SNP wGRS analyses yielded highly similar results.
