[Diagnostic transitions in adolescent inpatients with mental disorders: a retrospective cohort study]

To investigate diagnostic changes from baseline to final hospitalization and identify the major transition pathways among adolescent inpatients with mental disorders.

Adolescents aged 12-17 years at their first hospitalization, with an interval of at least 3 years between baseline and final hospitalization and at least two complete inpatient records, were included from the electronic medical record system of the Affiliated Mental Health Center of Zhejiang University School of Medicine (Hangzhou Seventh People's Hospital). Primary discharge diagnoses were grouped according to ICD-10. Overall and diagnosis-specific stability, transition patterns, heatmap and Sankey flows were analyzed. Multivariate logistic regression was used to explore factors associated with diagnostic inconsistency and with transition from non-severe mental illness (non-SMI) at baseline to SMI. Results are presented as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

A total of 741 patients were included. Baseline and final diagnostic categories were consistent in 409 patients (55.2%). The concordance rate was 77.5% (297/383) for baseline SMI and 31.3% (112/358) for baseline non-SMI. Reclassification within non-SMI categories was the most frequent inconsistency pattern (152, 20.5%), followed by non-SMI-to-SMI transition (94, 12.7%). Transitions were mainly clustered in reclassification within the affective spectrum and adjustments across the psychotic-affective boundary. Among patients with baseline depressive disorders, 61 were reclassified as other mood disorders, 22 as the combined manic episode/bipolar disorder category, and 10 as schizophrenia-spectrum disorders; among those with baseline schizophrenia-spectrum disorders, 36 were reclassified as the manic episode/bipolar disorder category. In multivariable models, baseline SMI was associated with lower odds of diagnostic inconsistency (aOR = 0.13, 95% CI: 0.09-0.18, P < 0.01). Among patients with baseline non-SMI, older age and male sex were associated with higher odds of transition to SMI (aOR = 1.48, 95% CI: 1.25-1.75, P < 0.01; aOR = 1.99, 95% CI: 1.20-3.32, P < 0.01).

Diagnostic transitions from baseline to final discharge were relatively concentrated, primarily involving reclassification within the affective spectrum, adjustments across psychotic-affective boundaries, and transitions from selected non-specific non-SMI categories to SMI.