Developmental coupling between obsessive-compulsive symptoms and psychotic-like experiences in youth: a four-wave longitudinal study.

Obsessive-compulsive symptoms (OCS) and psychotic-like experiences (PLEs) commonly emerge during late childhood and early adolescence and often co-occur. However, it remains unclear whether this overlap reflects stable between-person differences, within-person longitudinal coupling, or symptom-specific developmental pathways. Using four waves of data from 7,451 participants in the Adolescent Brain Cognitive Development Study, we examined OCS-PLEs coupling from late childhood to early adolescence. Parallel-process latent growth models characterized co-developmental trajectories; cross-lagged and random-intercept cross-lagged panel models distinguished between-person from within-person associations; and temporal network analyses identified symptom-level bridge patterns. OCS and PLEs followed distinct but partially coupled developmental trajectories, with higher initial OCS associated with higher initial PLEs and a less favorable trajectory of PLEs over time. Conventional cross-lagged models showed bidirectional associations at the observed-score level, whereas random-intercept models suggested that early associations largely reflected stable between-person differences; only PLEs predicted subsequent increases in OCS from ages 12 to 13 at the within-person level. Symptom-level networks showed earlier OCS-to-PLE links and later more reciprocal coupling, with intrusive thoughts and worry emerging as consistent bridge symptoms. These findings suggest that OCS-PLEs overlap may vary across developmental stages and highlight the importance of developmental timing and symptom-specific assessment in youth.