Patterns of health contacts for mental disorders among youth: a population-based administrative health data study in British Columbia, Canada (2008 to 2022)

This administrative health records study describes patterns in new health contacts for mental disorders and mental disorder complexity among youth (aged 10 to 24) in British Columbia (B.C.), Canada. Insights into mental health care in this population are needed to develop effective health service delivery models. We analyzed retrospective population-based administrative health data on an open cohort of youth aged 10 to 24 between January 1, 2008, and December 31, 2022 and who were eligible for, registered with, and had contact with the provincial public insurance program (N=597,273). Using ICD-9 and ICD-10 codes, we determined the count of new health contacts for five selected mental disorder diagnostic outcomes: combined mood/anxiety, conduct, substance use, schizophrenia and other psychotic disorders, and attention deficit hyperactivity disorders. We further classified these outcomes and differentiated single and co-occurring disorder diagnosis patterns. We calculated pairwise correlations for mental disorders classified as following the co-occurring disorder diagnosis pattern and cross-tabulated mental disorder outcomes by key demographic characteristics, including age, biological sex, and geography. We calculated and plotted crude 3-year repeated cross-sectional trends in incidence rates of new mental disorder health contacts and applied multivariate Poisson regression to estimate the age- and sex-adjusted risk of new mental disorder health contacts across the study period. During the study period, 52.4% (n=313,183) of the cohort had a new health contact for at least one of the five mental disorder categories. New health contacts for the combined mood/anxiety disorder diagnosis outcome were the most frequent overall, and predominantly followed a single disorder diagnosis pattern for this combined diagnostic category. Conduct, substance use, and schizophrenia and other psychotic disorders were less frequent overall and frequently followed the co-occurring diagnosis pattern. The crude incidence rate and adjusted risk of new mental disorder contacts increased during the study period. This study shows a growing demand for mental health care services among youth engaging with outpatient and inpatient health care. The increasing number of new health contacts for mental disorders among youth suggests that targeted services and greater resources may be needed to meet this growing demand.