Schizophrenia is actually eight different genetic disorders rolled into one, according to a new study released Monday.

The study, published in the American Journal of Psychiatry, found that there are different gene clusters that contribute to eight different classes of the usually hereditary disease. The researchers at Washington University in St. Louis analyzed the genes of more than 4,000 people with schizophrenia, and tallied the symptoms of patients against the DNA of people with and without schizophrenia in order to identify the gene clusters.

In patients experiencing hallucinations and delusions, the researchers found that the interaction between genetic variations created a 95% chance of schizophrenia, while disorganized speech and behavior in another set of patients revealed a set of variations associated with a 100% risk. The hereditary risk of schizophrenia is known to be about 80%.

“What we’ve done here, after a decade of frustration in the field of psychiatric genetics, is identify the way genes interact with each other, how the ‘orchestra’ is either harmonious and leads to health, or disorganized in ways that lead to distinct classes of schizophrenia,” said Dr. C. Robert Cloninger, one of the senior researchers in the study.

Another researcher, Igor Zwir, said that identifying groups of genetic variations and matching them to symptoms may lead to enhanced treatment by targeting specific genetic pathways.

Write to Rishi Iyengar at rishi.iyengar@timeasia.com.