People whose parents had separated in childhood could face an increased risk of developing psychotic illnesses than common people, says a new study.
The traditional view has been that psychosis such as schizophrenia is largely a genetic brain disease, and most psychiatrists have believed that social factors cannot have a major impact on them.
The new study by the Institute of Psychiatry here examined data on people in southeast London, Bristol and Nottingham, including 780 who showed signs of a psychotic illness, reported the online edition of BBC News.
They found schizophrenia was nine times more common in people from African Caribbean origin, and six times more common in people from black African origin than in the white British population.
In a second paper, they found that separation from one or both parents for more than a year before the age of 16, as a consequence of family breakdown, was associated with a 2.5-fold increased risk of developing psychosis in adulthood.
Family breakdown of this type was found to be more common in the African-Caribbean community (31 percent) than the white community (18 percent), said the study published in the journal Psychological Medicine.
"These findings provide evidence that early social adversity may increase the risk of later psychosis," said researcher Craig Morgan.
"Such early adversity may be one factor contributing to the high rate of psychosis in the African-Caribbean population," he added.