Mental Health Service Use Before First Diagnosis of a Psychotic Disorder

Importance Characterizing mental health service use trajectories preceding diagnosis of a psychotic disorder may help identify individuals at highest risk and in which settings they are at highest risk. Objective To examine mental health service use and diagnostic trajectories before first diagnosis of psychotic disorder and identify utilization and diagnostic patterns. Design, Setting, and Participants This population-based, retrospective cohort study used linked provincial health administrative data. The sample included individuals aged 15 to 29 years diagnosed with a psychotic disorder in Ontario, Canada, between April 1, 2012, and March 31, 2018. These individuals were matched to individuals with a diagnosis of a mood disorder. Data were analyzed from November 2018 to November 2019. Main Outcomes and Measures The main outcomes were rates, timing, and setting of mental health–related service use and associated diagnoses in the 3 years before the index disorder among individuals first diagnosed with a psychotic disorder compared with those first diagnosed with a mood disorder. Results A total of 10 501 individuals with a first diagnosis of psychotic disorder were identified (mean SD age, 21.55 3.83 years; 72.1% male). A total of 72.2% of individuals had at least 1 mental health service visit during the 3 years before their first psychotic disorder diagnosis, which was significantly more than matched controls with a first mood disorder diagnosis (66.8%) (odds ratio OR, 1.34; 95% CI, 1.26-1.42). Compared with individuals diagnosed with a mood disorder, individuals diagnosed with a psychotic disorder were significantly more likely to have had mental health–related hospital admissions (OR, 3.98; 95% CI, 3.43-4.62) and emergency department visits (OR, 2.27; 95% CI, 2.12-2.43) in the preceding 3 years. Those with psychotic disorders were more likely to have had prior diagnoses of substance use disorders (OR, 2.57; 95% CI, 2.35-2.81), other disorders (personality disorders, developmental disorders) (OR, 1.75; 95% CI, 1.61-1.90), and self-harm (OR, 1.64; 95% CI, 1.36-1.98) in the past 3 years compared with those diagnosed with mood disorders. Conclusions and Relevance This study found that in the 3 years prior to an index diagnosis, individuals with a first diagnosis of psychotic disorder had higher rates of mental health service use, particularly emergency department visits and hospitalizations, compared with individuals with a first diagnosis of a mood disorder. Individuals with psychotic disorders also had a greater number of premorbid diagnoses. Differences in health service utilization patterns between those with a first psychotic disorder diagnosis vs a first mood disorder diagnosis suggest distinct premorbid trajectories that could be useful for next steps in prediction and prevention research.