Prevention has been defined as intervention that occurs before the onset of a clinically diagnosable disorder that aims to reduce the number of new cases of that disorder. Preventative methods therefore, may be viewed as any attempt to prevent entry to, or progression along, the trajectory towards a severe, debilitating psychological disorder. While depression is only one of many psychological disorders with which adolescents may be afflicted, there are many important reasons why the disorder should be the focus of preventative efforts. This chapter examines these reasons, and details the prevention programs to date that have targeted adolescent depression. The chapter concludes with a brief outline of the problem solving for life program (PSFL), a universal program aimed at preventing adolescent depression. PSFL course is associated with increased social problem-solving ability, and decreased depressive symptoms in both high- and low-risk intervention groups from pre- to post-intervention. That such effect was found in such a large sample and with both high and low-risk subjects are very encouraging for universal prevention research. The project now progress to examine the longer-term impact of PSFL in order to determine whether the positive benefits are maintained.