Anxiety and depression symptoms (measured by the Profile of Mood States, McNair et al. 1992) were available in a population cohort aged 52±16 years. General psychological distress was indexed by a composite score of anxiety and depression. GWAS data (Illumina HumanHap300 chip) were available for 527 (54% females) participants. For QC of the GWAS data see Stefannson et al. (2008). A linear regression was performed including the covariates age, sex and the first three MDS components in PLINK (Purcell et al. 2007).
