The GWA meta-analyses were performed on personality data collected from nine samples: SardiNIA–Italy,26, 27 Erasmus Rucphen Family study (ERF)–The Netherlands,28 Study of Addiction: Genetics and Environment (SAGE)–United States of America,29 Helsinki Birth Cohort Study (HBCS)–Finland,30, 31, 32 Nicotin Addiction Genetics Study/Interactive Research Project Grants (NAG/IRPG) study–Australia,33, 34 Queensland Institute of Medical Research (QIMR) adolescent study–Australia,35, 36 Lothian Birth Cohort 36 (LBC36)–United Kingdom,37 Baltimore Longitudinal Study of Aging (BLSA)–United States of America38 and Estonian Genome Project of University of Tartu (EGPUT)–Estonia.39 For a detailed description of these samples, we refer to de Moor et al.25 The total number of subjects available for the meta-analyses was 13 835. Sample sizes ranged from 600 to 3972 individuals. Mean age ranged from 19 to 70 years. In 5 studies, the mean age was between 40 and 50 years, in 1 study the mean age was 19 years, and in 3 studies, the mean age was between 60 and 70 years. It must be noted that the meta-analysis as described in de Moor et al.25 also included the GAIN-MDD sample. This sample was excluded in
