While, at this point, this trade-off is unavoidable in population studies (save sampling the highly selected population of neurosurgical patients, for whom only a limited sampling of tissues can be harvested), future work attempting to validate postmortem brain epigenetic markers and/or to understand the relationship between epigenetic modification in the peripheral tissues with that in the brain may be fruitful. Moreover, future work in brain imaging to identify functional magnetic resonance images correlating to gene expression—and ideally epigenetic modification—would allow us a real-time view of the role of epigenetic modification in psychopathology. Access to suitable proxies for epigenetic modification in real-time would also allow for a life course understanding of the role of epigenetic modification in psychiatric disease, which would move us well beyond our current understanding of the role of epigenetic processes in psychopathology.
