The Erasmus Rucphen Family study subsample included 1160 participants from the Erasmus Rucphen Family (ERF) study, part of the Genetic Research in Isolated Population (GRIP) program (Aulchenko et al., 2004). The Center for Epidemiologic Studies Depression Rating Scale (CES-D) (Radloff, 1977; Zigmond and Snaith, 1983) (Spinhoven et al., 1997; Weissman et al., 1977) was used to define depression using a cut-off of CES-D ≥ 16 as indicative of a depressive disorder (Luijendijk et al., 2008).
