Developmental shift in the functional role of mind-wandering: A large-scale study on adaptive resources against depression in psychiatric outpatients.

PURPOSE: Mind-wandering (MW) is a transdiagnostic process, yet its functional evolution across the lifespan remains poorly understood. This study investigated developmental differences in how spontaneous (MW-S) and deliberate (MW-D) mind-wandering relate to depressive symptoms, specifically whether MW-D emerges as a potential protective factor in adulthood.

METHODS

We analyzed data from 1,079 psychiatric outpatients (732 adolescents; 347 adults). Assessments included the Autism-Spectrum Quotient, MW-S/MW-D scales, and the Quick Inventory of Depressive Symptomatology (excluding the suicidal ideation item). Hierarchical multiple regression (controlling for diagnosis) and ANOVA were employed to examine the interplay between age and MW dimensions.

RESULTS

While MW-S consistently associated with higher depressive symptoms, a notable developmental shift was observed for MW-D. In adolescents, MW-D showed no significant association with depression (p = .326). Conversely, for adults, MW-D emerged as a marginal negative predictor (β = -0.095, p = .078). A significant age-by-diagnosis interaction revealed that individuals with ASD traits exhibited a unique increase in MW-D during the transition to adulthood, a trajectory not found in non-neurodevelopmental groups.

CONCLUSION

The role of intentional reflection (MW-D) evolves from a non-specific trait in youth to a potential protective resource in adulthood. For adult outpatients, particularly those with neurodevelopmental traits, deliberate thought may function as an adaptive resource to mitigate distress. Clinical interventions should move toward fostering adaptive, intentional thought processes.