Adolescent mothers are at high risk of experiencing intimate partner violence (IPV) which may increase their likelihood of depressive symptoms in adulthood, yet little is known about the long-term effects of IPV on adolescent mothers' trajectories of depressive symptoms. The study reported here uses prospective data spanning 14 years from a study of 229 adolescent mothers from Washington State, USA to evaluate the effects of adolescent exposure to IPV on the trajectories of depressive symptoms over time, as well as the likelihood of depressive symptoms at age 28 years. After controlling for levels of economic insecurity, the results indicate that adolescent IPV and an early vulnerability to depression were significantly related to the intercept, but not the slope of the adult depressive symptom trajectories. Both cumulative and concurrent IPV predicted the likelihood of depressive symptoms at age 28 years. Follow-up analyses indicate that adolescent IPV is associated with greater levels of adult IPV, and that women who report both adolescent and adult IPV have the highest mean levels of depressive symptoms. These findings suggest that exposure to IPV in adolescence may alter the life course of young women, increasing their risk for continuing exposure to intimate partner violence in adulthood and its concomitant negative mental health effects. Efforts aimed at prevention and early intervention in IPV among adolescent mothers are important components of the clinical care of young mothers.