Study Examines Risk for Psychiatric Disorders in Offspring of Mentally Ill Parents

A child's risk for bipolar disorder or schizophrenia may be directly impacted by having one or more parents with the condition.

The results of a new study show the risk for schizophrenia or bipolar disorder that children face when they have one or more parents who were or were not diagnosed with one of these illnesses.

Researchers from the University of Minnesota Medical School and Aarhus University in Denmark examined the mental health of children for whom both parents, only one parent, or neither parent had been admitted to a psychiatric facility because of bipolar disorder. Among the “146 offspring of 83 parent couples who were ever admitted with bipolar disorder,” the risk of the disorder was 24.9%, which increased to 36% when “unipolar depressive disorder was included.” This figure was compared to 23,152 offspring from 11,995 couples with only one parent ever admitted for bipolar disorder (4.4% at risk) and also to 2,239,553 offspring of 1,080,030 couples with neither parent ever admitted (0.48% at risk).

The researchers also examined the mental health of children for whom both parents, only one parent, or neither parent had ever been admitted to a psychiatric facility for schizophrenia. In the group of 270 offspring of 196 parent couples in which both parents had been admitted with a diagnosis of schizophrenia, the risk of schizophrenia in the offspring was 27.3%, which increased to 39.2% when schizophrenia-related disorders were included.

This population-based cohort study involved 2.7 million people in Denmark who were either born in or later than 1968. The individuals also had to have a registered link to their mother and father and needed to be 10 years or older in 2007.

“Derived risks may be informative for counseling,” the researchers concluded in the Archives of General Psychiatry abstract. “Patterns of transmission may support evolving assumptions about genetic overlap for traditional categories.”