A Genome Wide Association study of Unipolar Depression

Depressive disorder is a very common condition that is substantially influenced by heredity. However genetic basis is complicated, involves an interplay with environmental stress and is , so far, not well understood at a molecular level. This study aims to identify genes involved in susceptibility to depression.It will have important implications for the future discovery of novel targets for new safer, more effective medications.

We will carry out a genome wide association (GWA) study using a very large sample (N~4,700) of white European cases of well defined unipolar depression (minimum 2 severe episodes) and a set of ethnically matched super controls screened for lifelong mental health (N~2400). The samples to be genotyped comprise white European subjects collected by ourselves and colleagues - cases: 3,736 and screened ?super controls?: 1,500. In addition we will add GSK data already generated on 943 white German cases defined in exactly the same way as our own cases and 868 ethnically matched ?super controls?.
We will further examine our top 500 ?hits? against white European controls from the Wellcome Trust?s Case Control Consortium (N~3,000), a GSK control collection (N~4,000), and an Illumina control panel (N~10,000).
We will use the GSK comprehensive annotation of SNPs as well as information from recent linkage studies to select targets that merit further detailed investigation, including additional genotyping where indicated.
We will compare our findings with those from a GWA study currently underway in the US (N~1, 800 cases, 1, 800 controls) and subsequently will participate in a GWA combined/meta-analysis study consortium.
The study promises to identify novel loci involved in the aetiology of unipolar depression.