Examine the developmental pathways through which the Family Bereavement Program (FBP) reduces major depression and generalized anxiety disorders 15 years later. A randomized trial of the FBP included five assessments, at pre-test, post-test (98% retention), and follow-ups at 11-months (90% retention), six (89% retention) - and fifteen (80% retention) years following the program. Participants include 244 children (from 156 families) ages 8 - 16 randomly assigned to the FBP (135 children, 90 families), a 12-session program that included a caregiver component and a child/adolescent component or a literature comparison condition (109 children, 66 families). In home interviews assessed mediators directly targeted for change at posttest and 11-months (e.g., parenting and coping); six-year theoretical mediators (i.e., internalizing problems, aversive views of the self) and 15-years children's major depression and generalized anxiety disorder. Data analysis tested three path mediation models in which FBP effects at post-test and 11-months lead to effects on six-year theoretical mediators, which in turn lead to reductions in major depression and generalized anxiety disorder at 15-years. The FBP had a significant effect to reduce the prevalence of major depression (OR =.332, p < .01) at 15-years. Significant three path mediation models found that multiple variables that were targeted by the caregiver and child components of the FBP at posttest and 11-months mediated FBP effects on depression at 15-years through their impact on aversive self-views and internalizing problems at 6-years. The findings support the 15-year impact of the Family Bereavement Program on major depression and for maintaining components of the FBP that impact aspects of parenting and children's coping, grief and self-regulation as the program is disseminated.