Genomics research of lifetime depression in the Netherlands: The BIObanks Netherlands Internet Collaboration (BIONIC) project

The BIONIC (BIObanks Netherlands Internet Colalboration) project represents a nation-wide 
collaboration among population cohorts in the Netherlands. Within this collaboration we developed 
a standardized online instrument for the assessment of DSM-based diagnosis of major depressive 
disorder (MDD), which was validated and showed a twin family-based heritability of 35%. Next, 13 
cohorts in the Netherlands collected MDD data and agreed to share the phenotype and genotype 
data for genome-wide association studies (GWAS), enabling mega- and meta-analyses. Phenotype 
data include MDD diagnoses and also data on sociodemographics, lifestyle and other mental health 
information. We have established a database of N = 132,850 adults. The lifetime prevalence of MDD 
in this sample is 18.1% which complies with prevalence estimates of other studies in the 
Netherlands. Currently, N = 66,648 individuals in the BIONIC set also have genome-wide SNP data. As 
different cohorts obtained SNP data from different arrays, we developed a strategy to optimally 
combine array data and implemented a centralized pipeline for genotype imputation that we 
describe in this paper, together with the phenotypic sample characteristics. 
Key words: national cohort studies, MDD assessment, GWAS resource