Wellbeing (WB) encompasses states of happiness, optimism and life satisfaction. There is much evidence that WB affects immune function and health in general. Both genetic and environmental factors influence WB. According to twin studies, it is 40% heritable. Epigenetic mechanisms like DNA methylation respond to the environment and regulate the activity of genes, they may therefore mediate the affects of environment on WB. Indeed a recent study found associations between WB and DNA methylation in peripheral blood (Baselmans et al., 2015). We plan to test these associations in ALSPAC as part of a multi-study meta-analysis of WB in DNA methylation. We will focus on data collected in middle age when WB is lowest.