A large literature finds that cognitive behavioral therapy programs for disruptive students can reduce their disruptiveness and improve their academic outcomes. However, the literature has mostly considered demonstration programs implemented with significant researcher involvement, and has not studied the spillover effects on ineligible students. In this paper, we use a randomized controlled trial to estimate the direct and spillover effects of one such program, implemented as a nationwide policy in Chile. The program has no effect on eligible students' disruptiveness and academic outcomes. It increases the disruptiveness of ineligible students. Finally, it increases the segregation between eligible and ineligible students. * We thank the Junta Nacional de Auxilio Escolar y Becas (JUNAEB) for allowing us to randomize the timing of the Habilidades para la vida program, and for providing us with some of the data used in this research.