Severe injuries in adolescence predict psychosis: a nested case control study of the Northern Finland 1966 Birth Cohort

Adolescents who later develop schizophrenia are likely to have problems with motor coordination and many adolescents with schizophrenia have self-injurious behaviour before treatment of first psychosis but association between injuries in adolescence and onset of psychotic disorder is unknown. The aim of this study was to describe what type of injuries psychotic individuals had during adolescence and in which age these injuries occurred. The study population consists of 155 members of the Northern Finland 1966 Birth Cohort with diagnosis of schizophrenia spectrum disease and 620 matched controls. All injuries which had occurred before onset of psychosis were extracted from Finnish Hospital Discharge Register. Individuals with psychotic disorder were more likely to have a history of severe injury. During the age 12-19, 11% of psychotic subjects and 5.3% of healthy controls had an injury (z=2.38; P=0.017) and the most common type of injury was fractures. Our findings suggest that severe injury in adolescence may be a predictor of psychosis.