Minor physical anomalies and schizophrenia spectrum disorders: A prospective investigation

Objective. The authors prospectively assessed the relationship between minor physical anomalies identified in childhood and adult psychiatric outcome. Method: In 1972, minor physical anomalies were measured in a group of 265 Danish children ages 11-13. The examination was part of a larger study investigating early signs of schizophrenia spectrum disorders. Many of the subjects had a parent with schizophrenia, leaving them at high risk for developing a schizophrenia spectrum disorder. In 1991, adult psychiatric outcome data were obtained for 91.3% (N=242) of the original subjects, including 81 who were at high risk. Results: individuals with a high number of minor physical anomalies developed schizophrenia spectrum disorders significantly more often than they developed a no mental illness outcome. Further, individuals with a high number of minor physical anomalies tended to develop schizophrenia spectrum disorders more often than other psychopathology. Among individuals at genetic high risk, higher numbers of minor physical anomalies may interact with pre-existing vulnerabilities for schizophrenia to increase the likelihood of a schizophrenia spectrum disorder outcome. Conclusions: Minor physical anomalies may provide important clues to understanding schizophrenia spectrum disorders from a neurodevelopmental perspective. Minor physical anomalies appear to signal stressors relevant to schizophrenia spectrum development, especially in those at genetic risk for schizophrenia.