There is a long history of research on the familial transmission of schizophrenia and other psychoses. However, few studies have investigated the specificity of the transmission of schizophrenia-psychosis spectrum (SPS) disorders and affective psychoses (APs) or observed high-risk offspring into mid-adulthood.
To investigate the transmission of psychoses from parents to their offspring and the specificity of transmission across psychosis subtypes.
High-risk follow-up study.
New England Family Study's High-Risk Study, with population-based community sampling from Boston, Massachusetts, and Providence, Rhode Island.
A total of 203 high-risk offspring of 159 parents with diagnoses of psychoses (SPS and AP) and 147 control offspring of 114 control parents.
Main Outcome Measures
Systematically assessed research DSM-IV psychiatric diagnoses for adult offspring.
Compared with those of control parents, offspring of parents with SPS had a significant, almost 6-fold elevated risk of SPS disorders and a nonsignificant doubling of risk for AP. Offspring of parents with AP had a significant 14-fold elevated risk for AP compared with offspring of controls; for SPS disorders, the risk doubled but was not significant.
Having a parent with psychosis significantly increased the risk for psychosis among offspring and demonstrated specificity for the transmission of SPS disorders and APs within families.