In summary, our strongest GWAS finding was for a SNP near MGAT5 and NCKAP5, which was suggestively associated with depression symptoms and replicated in two cohorts. Our gene based test identified a locus on chromosome 15 associated with neuroticism, and this region was also replicated. Single SNP results often generalised across multiple traits, particularly neuroticism and depression, and by using genetic personality profile scores we were able to predict (in the hypothesised direction) symptoms of depression from neuroticism polygenic scores. In the replication cohorts, all mood states were predicted by extraversion polygenic scores (in the German cohort) and psychological distress from neuroticism polygenic scores (in the NTR). Future work should encompass multivariate genetic association analysis of personality traits and mood states because the covariance among these variables might more reliably index people at greater genetic predisposition to psychological distress by removing environmental variance affecting mood. Some of our results have been linked previously to clinical psychiatric traits, suggesting that personality and mood traits sampled in the general population may be relevant to clinical pathology of mood.
