Nature versus nurture: when does the environment affect schizophrenia?
New research from Johns Hopkins School of Medicine (MD, USA) looks to settle controversy over the epigenetic cause of schizophrenia, demonstrated that it the prenatal period during which the environment causes epigenetic changes in the brain.
A team from Johns Hopkins School of Medicine (MD, USA) has recently released results from one of the largest studies of post-mortem brain tissue to date that sheds new light on the nature versus nurture debate in schizophrenia.
While many theories suggest that a stressful environment in early adulthood is associated with the onset of schizophrenia, this is hotly debated. The group set out to take a ‘molecular snapshot’ of when the brain is affected by the environment, and demonstrated that it is in fact the prenatal period where the environment causes epigenetic changes in the brain.
Utilizing DNAm from 335 non-psychiatric controls and 191 patients with schizophrenia, they analyzed methylation changes in the transition from prenatal to postnatal life, and into early adulthood. With 2104 CpGs differing between schizophrenic patients and controls, they found that changes in methylation associated with schizophrenia were linked to the early developmental period, rather than early adulthood as they expected.
“The results suggest that the epigenetic changes that leave a lasting mark in the brains of patients with schizophrenia harken back to early brain development – long before the first symptoms of the illness are recognized,” commented Andrew Jaffe, lead investigator. “In other words, the building of the brain early in life is key to understanding schizophrenia, and the events around the apparent onset of the illness may be a ‘red herring’.”
Daniel R Weinberger, co-leader of the team, commented further: “This conclusion, while perhaps not the final verdict on the subject, is hard to resist given this remarkable evidence. These results have potentially far-reaching implications for how we understand schizophrenia, how we develop experimental models of this illness in scientific laboratories, how we search for new ways to prevent the disorder from happening, and how we treat it once it does.”
Sources: www.businesswire.com/news/home/20151130006174/en/Major-Study-Rewrites-Nature-v.-Nurture-Debate; Jaffe AE, Gao Y, Deep-Soboslay A et al. Mapping DNA methylation across development, genotype and schizophrenia in the human frontal cortex. Nature doi:10.1038/nn.4181 (2015) (Epub ahead of print).