This study used a genetically controlled design to examine the direction and the magnitude of effects in the over-time associations between perceived relationship quality with mothers and adolescent maladjustment (i.e., depressive symptoms and delinquency). A total of 163 monozygotic (MZ) twins pairs (85 female pairs, 78 male pairs) completed questionnaires at ages 13 and 14. Non-genetically controlled path analyses models (in which one member of each twin dyad was randomly selected for analyses) were compared with genetically controlled path analyses models (in which MZ-twin difference scores were included in analyses). Results from the non-genetically controlled models revealed a) child-driven effects in the longitudinal associations between adolescent perceived maternal support and depressive symptoms, and b) parent-driven and child-driven effects in the longitudinal association between perceived maternal negativity and adolescent delinquent behaviors. However, results from the genetically controlled models revealed only child-driven effect, suggesting that, purported parent-driven effects were a product of error arising from potential gene-environment correlations (rGE).