Common ground discovered in mental illness

New research has found that common psychiatric disorders such as schizophrenia, bipolar disorder and major depression share genetic risk factors related to immune function and DNA regulation.

The study, led by Dr. Gerome Breen at King's College London and Prof. Peter Holmans at Cardiff, in collaboration with researchers at UCLA and the Broad Institute of Harvard and MIT, was conducted by the Pathways Subgroup of the Psychiatric Genomics Consortium, which involves hundreds of investigators from dozens of institutions across the globe.  It is published online today in Nature Neuroscience.

Thousands of genetic differences across the human genome act together to increase the risk for psychiatric conditions such as schizophrenia. However, until now, it has not been clear how these genetic changes affect different biological processes that then go on to alter brain function.

Dr Gerome Breen, MRC Centre for Social Genetic and Developmental Psychiatry at King's, Professor Peter Holmans, MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff University, and colleagues, analyzed genetic data from over 60,000 participants, including individuals with schizophrenia, bipolar disorder, major depression, autism spectrum disorders and attention deficit hyperactivity disorder, as well as healthy individuals. Their aim was to identify the biological and biochemical pathways involved in causing risk for these disorders.

Professor Peter Holmans from Cardiff University noted: 'The use of genome-wide genetic data allows us to identify disease-relevant pathways without making prior biological assumptions.  This is important as it allow us to discover novel mechanisms of risk that might not otherwise be studied.' 

Dr Breen said: 'When we grouped the genetic data together, we found that genes relating to histone methylation - molecular changes that alter DNA expression - and immune function are risk factors associated with the development of these disorders. Biological pathways are important as they are much broader drug targets than single genes or proteins.'