[The study] was based on an examination of genetic data from more than 60,000 people world-wide. Its authors say it is the largest genetic study yet of psychiatric disorders. The findings strengthen an emerging view of mental illness that aims to make diagnoses based on the genetic aberrations underlying diseases instead of on the disease symptoms.
Two of the aberrations discovered in the new study were in genes used in a major signaling system in the brain, giving clues to processes that might go awry and suggestions of how to treat the diseases.
The new study does not mean that the genetics of psychiatric disorders are simple. Researchers say there seem to be hundreds of genes involved and the gene variations discovered in the new study only confer a small risk of psychiatric disease.
Steven McCarroll, director of genetics for the Stanley Center for Psychiatric Research at the Broad Institute of Harvard and M.I.T., said it was significant that the researchers had found common genetic factors that pointed to a specific signaling system.
"It is very important that these were not just random hits on the dartboard of the genome," said Dr. McCarroll, who was not involved in the new study.
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