Symptom Complexity Subtypes Show Distinct Individualism–Collectivism Orientations in Adolescents With Depressive Episodes, With Loneliness Mediating Their Relationship

INTRODUCTION: Adolescent depressive episodes exhibit significant symptom complexity and heterogeneity, necessitating an integrated approach to identify distinct subtypes. Cultural orientations (individualism and collectivism) and loneliness are crucial factors impacting adolescent mental health. This study identifies symptom complexity subtypes in Chinese adolescents with depressive episodes, investigates cultural orientation differences between these subtypes, and explores the role of loneliness. METHODS: A total of 110 adolescents were included. K-means clustering was used to generate symptom complexity subtypes based on disease duration, self-injury, mood disorder, depressive, and anxiety symptoms. Cultural orientations were assessed using the Individualism-Collectivism Scale, loneliness using the UCLA Loneliness Scale, and other relevant variables were collected via self-report. Structural equation modeling (SEM) was used to explore associations among cultural orientations, loneliness, and symptom complexity. RESULTS: Two subtypes were identified: low-complexity and high-complexity. The high-complexity subtype exhibited elevated loneliness levels (t = -6.16, p < 0.001), more severe childhood trauma and bullying, and greater social media addiction. This group also reported higher vertical individualism (t = -2.02, p = 0.046) and lower vertical collectivism (t = 2.05, p = 0.043). SEM revealed a significant indirect association between higher individualism tendency and increased symptom complexity mediated by loneliness (β = 0.21, p < 0.001 and β = 0.53, p < 0.001, respectively). DISCUSSION: Incorporating cultural orientation assessments into clinical practice may improve treatment outcomes for adolescents with depressive episodes by identifying those at risk for complex symptom presentations and informing subsequent culturally-tailored therapeutic interventions.