Genome-wide association of major depression: description of samples for the GAIN Major Depressive Disorder Study: NTR and NESDA biobank projects.

To identify the genomic regions that confer risk and protection for major depressive disorder (MDD) in humans, large-scale studies are needed. Such studies should collect multiple phenotypes, DNA, and ideally, biological material that allows gene expression analysis, transcriptomic, proteomic, and metabolomic studies. In this paper, we briefly review linkage studies of MDD and then describe the large-scale nationwide biological sample collection in Dutch twin families from the Netherlands Twin Register (NTR) and in participants in the Netherlands Study of Depression and Anxiety (NESDA). Within these studies, 1862 participants with a diagnosis of MDD and 1857 controls at low liability for MDD have been selected for genome-wide genotyping by the US Foundation for the National Institutes of Health Genetic Association Information Network. Stage 1 genome-wide association results are scheduled to be accessible before the end of 2007. Genome-wide association results are open-access and can be viewed at the dbGAP web portal (http://www.ncbi.nlm.nih.gov). Approved users can download the genotype and phenotype data, which have been made available as of 9 October 2007

Genome-wide association scan for five major dimensions of personality

Personality traits are summarized by five broad dimensions with pervasive influences on major life outcomes, strong links to psychiatric disorders and clear heritable components. To identify genetic variants associated with each of the five dimensions of personality we performed a genome-wide association (GWA) scan of 3972 individuals from a genetically isolated population within Sardinia, Italy. On the basis of the analyses of 362 129 single-nucleotide polymorphisms we found several strong signals within or near genes previously implicated in psychiatric disorders. They include the association of neuroticism with SNAP25 (rs362584, P= 5 x 10(-5)), extraversion with BDNF and two cadherin genes (CDH13 and CDH23; Ps<5 x 10(-5)), openness with CNTNAP2 (rs10251794, P= 3 x 10(-5)), agreeableness with CLOCK (rs6832769, P= 9 x 10(-6)) and conscientiousness with DYRK1A (rs2835731, P= 3 x 10(-5)). Effect sizes were small (less than 1% of variance), and most failed to replicate in the follow-up independent samples (N up to 3903), though the association between agreeableness and CLOCK was supported in two of three replication samples (overall P= 2 x 10(-5)). We infer that a large number of loci may influence personality traits and disorders, requiring larger sample sizes for the GWA approach to confidently identify associated genetic variants. Molecular Psychiatry (2010) 15, 647-656; doi: 10.1038/mp.2008.113; published online 28 October 200

Affective Reactivity to Daily Stressors and Long-Term Risk of Reporting a Chronic Physical Health Condition

BACKGROUND: Daily stressors, such as an argument with a spouse or an impending deadline, are associated with short-term changes in physical health symptoms. Whether these minor hassles have long-term physical health ramifications, however, is largely unknown. PURPOSE: The current study examined whether exposure and reactivity to daily stressors is associated with long-term risk of reporting a chronic physical health condition. METHODS: Participants (N = 435) from the National Study of Daily Experiences completed a series of daily diary interviews between 1995 and 1996 and again 10 years later. RESULTS: Greater affective (i.e., emotional) reactivity to daily stressors at Time 1 was associated with an increased risk of reporting a chronic physical health condition at Time 2. CONCLUSION: Results indicate that how people respond to the daily stressors in their lives is predictive of future chronic health conditions