Fresh mutations are involved in at least half of schizophrenia cases when there is no family history of the illness
A report in the journal Nature Genetics showed that "fresh mutations" in DNA are involved in at least half of schizophrenia cases, when there is no family history of the illness.
Researchers found mutations in 40 different genes.
Lead researcher Dr Maria Karayiorgou said: "The fact that the mutations are all from different genes is particularly fascinating.
"It suggests that many more mutations than we suspected may contribute to schizophrenia. This is probably because of the complexity of the neural circuits that are affected by the disease; many genes are needed for their development and function."
The report argues that this "provides a plausible explanation for both the high global incidence and the persistence of schizophrenia despite extremely variable environmental factors."