Familial Mental Illness Risk Cuts Across Disorders

A new meta-analysis of familial mental illness risks shows that children in a family where members have a history of serious mental illness appear to be at elevated risk of developing a mental disorder by the time they are adults.

The most important finding from the analysis, said lead researcher Rudolf Uher, M.D., in an interview with Psychiatric News, “is that familial risk cuts across disorders. . . . When we look at all types of mental illness, the risk is alarmingly high.” Uher is an assistant professor of psychiatry at Dalhousie University in Canada.

A key clinical implication of the findings, he added, is “that family history of mental illness is important. We should urgently look into how we may help the sons and daughters of parents with mental illness develop resilience.”

Uher and his colleauges included in their meta-analysis 33 well-conducted studies on the risk of mental illness in the offspring of individuals with a lifetime history of one of three types of mental illness—schizophrenia or nonaffective psychosis, bipolar disorder, or major depressive disorder. The meta-analysis included 7,021 offspring—3,863 offspring of a parent with one of these three disorders and 3,158 offspring of mentally healthy parents matched on demographic characteristics.

The children of parents with a lifetime history of schizophrenia, bipolar disorder, or major depressive disorder had about a 1 in 3 chance of developing one of these illnesses themselves by adulthood, the researchers found. The risk was more than twice that for control offspring.

Furthermore, compared with control offspring, the offspring of parents with one of the three mental disorders were almost four times more likely to have the same disorder as their parent and almost twice as likely to have one of the two other disorders assessed in the study.

The researchers reported their findings in the January Schizophrenia Bulletin. The research was funded by the Canadian Institutes of Health Research, the Nova Scotia Health Research Foundation, the European Commission, the Dalhousie Clinical Research Scholar Program, and Genome Quebec. ■