This chapter discusses the degree to which suicidal behaviour co-occurs with substance abuse for adolescents, and possible reasons for this interrelationship. An integrated relapse prevention (RP) approach may be advantageous for patients in underscoring the relationship between substance use and STBs and how a common or complementary set of skills can be used to address both sets of problems. Namely, there are few established integrated RP approaches and patients with both sets of problems are often referred to separate providers and agencies to address each problem. Not only may this be burdensome for patients, but it increases the chances of lack of communication and coordination, including the possibility of contradictory treatment recommendations from each provider. Clinically, the treatment of suicidal youths is often much more difficult when youths are abusing substances. Likewise, treatment of substance use problems in adolescence can be considerably more difficult when youths are experiencing serious suicidal thoughts and engaging in suicidal behaviours.