Identifying Distinct Depression Trajectories in Korean Parents of Individuals With Intellectual Disability or Autism Spectrum Disorder: A Growth Mixture Modeling Analysis

This study examined heterogeneous longitudinal patterns of depression among parents caring for individuals with intellectual disability (ID) or autism spectrum disorder (ASD), identifying distinct trajectory classes and their associated baseline predictors and distal psychosocial correlates. Growth mixture modeling (GMM) was applied to five waves of annual data (2018 – 2022) from the Korean Disability and Life Dynamics Panel, comprising 680 parents of individuals with ID or ASD. Three distinct depression trajectory classes emerged, with moderate classification certainty (entropy = .58). Nearly one-third of parents (34.53%; High-Level Persistent Class) maintained persistently elevated self-reported depressive symptoms throughout the five-year period. An additional 15.44% (Moderate-Level Stable Class) showed moderately stable depression with no significant change. The largest group (50.03%; Low-Level Decreasing Class) exhibited low initial depression with a gradual decline over time. Trajectory class membership was significantly associated with child age, disability type, severe economic deprivation, and parental experience of discrimination. At Year 5, the High-Level Persistent Class demonstrated significantly less favorable distal psychosocial correlates across all domains, particularly in self-esteem and family functioning. These findings demonstrate that parental depression is not a uniform experience but follows qualitatively distinct developmental trajectories, each linked to a distinct pattern of baseline predictors and distal psychosocial correlates. A tiered support model addressing distinct risk profiles may be warranted, rather than a uniform approach applied across this heterogeneous population.