Cells in the human brain appear to survive and function for decades. Molecular changes to existing cells are therefore essential for development and to effectively respond to the environment. DNA methylation represents an important set of such molecular changes and aberrant methylation patterns have already been associated with a variety of psychiatric disorders.
However, the brain methylome is very large (~1 billion sites) and complex. Although methods exist to measure the brain methylome, they are too expensive to be used in studies aimed at finding the methylation changes in brain that are associated with psychiatric disorders.
We have therefore developed an approach that allows comprehensive and cost-effective investigations of the entire brain methylome. Specifically, we showed that this approach has approximately the same performance as the expensive approaches but achieves this at <5% of the costs. Being the only viable option currently available for comprehensive brain methylome studies, this approach may be critical for moving the field forward.