Testing transactional processes between parental support and adolescent depressive symptoms: From a daily to a biennial timescale.

Transactional processes between parental support and adolescents' depressive symptoms might differ in the short term versus long term. Therefore, this multi-sample study tested bidirectional within-family associations between perceived parental support and depressive symptoms in adolescents with datasets with varying measurement intervals: Daily ( = 244, = 13.8 years, 38% male), bi-weekly ( = 256, = 14.4 years, 29% male), three-monthly ( = 245, = 13.9 years, 38% male), annual ( = 1,664, = 11.1 years, 51% male), and biennial ( = 502, = 13.8 years, 48% male). Preregistered random-intercept cross-lagged panel models (RI-CLPMs) showed negative between- and within-family correlations. Moreover, although the preregistered models showed no within-family lagged effect from perceived parental support to adolescent depressive symptoms at any timescale, an exploratory model demonstrated a negative lagged effect at a biennial timescale with the annual dataset. Concerning the reverse within-family lagged effect, increases in adolescent depressive symptoms predicted decreases in perceived parental support 2 weeks and 3 months later (relationship erosion effect). Most cross-lagged effects were not moderated by adolescent sex or neuroticism trait level. Thus, the findings mostly support adolescent-driven effects at understudied timescales and illustrate that within-family lagged effects do not generalize across timescales.