HAVE SCHIZOPHRENIA SPECTRUM DISORDERS AMONG CHILDREN AND ADOLESCENTS INCREASED IN THE 2010s

ABSTRACT Background: The demand for child and adolescent mental health services and psychiatric care has increased significantly in Western countries during the 21st century. Schizophrenia spectrum disorders and schizophrenia itself are rare but severe conditions, and their incidence has been assumed to rise alongside the increase in general psychiatric symptoms. Objective: Our aim was to examine the absolute numbers and incidence proportions of schizophrenia spectrum disorders and schizophrenia during the 2010s and to compare the findings with those from previous decades, among children and adolescents in contact with specialist level psychiatric services. Materials and Methods: The study population consisted of all under 18-year-old patients who had contact with specialized psychiatric services between 2010 and 2019. They were identified from the Finnish Care Register for Health Care (HILMO), and psychiatric primary diagnoses were based on the ICD-10 classification. To compare changes across earlier decades, data from adolescents with their first inpatient contact in specialized psychiatric care between 1980 and 2009 were utilized. Statistical analyses included chi-square tests to assess differences between groups and Cox proportional hazards regression models to estimate risk. Results: The disorders were rare, and neither the number of diagnosed cases nor the risk of developing the disorder changed during the 2010s. The number of patients with schizophrenia spectrum diagnoses admitted for their first psychiatric inpatient treatment decreased compared to the previous decade, and the number of schizophrenia diagnoses has declined steadily since the 1980s. However, the absolute number of schizophrenia spectrum disorders stabilized at a higher level in the 2000s compared to earlier decades. Conclusions: Schizophrenia spectrum disorders have not increased among children and adolescents during 2010s. The variation in the number of schizophrenia spectrum disorders across decades with eventual stabilization at a higher level is likely due to changes in diagnostic practices. However, these severe disorders appear to be less influenced by broader societal changes than other disorders.