Transitioning from high school is known to be challenging for students. Utilising the Preferred Reporting Items for Systematic Reviews and Meta-analysis for scoping review guidelines, this scoping review examined the extent of existing research on the association of career indecision with depression, negative thoughts, and the role of self-efficacy and sense of control among school leavers. The extensive database search indicated only nine studies met the specified inclusion criteria. Results showed that more decided high school students tended to have more positive affect and higher levels of well-being. Conversely, levels of depression were found to be higher in less decided adolescents, with a direct relationship as well as the possible causal relationship indicated. The results indicate that integrated counselling in vocational and mental health support services is needed in schools through the leaving years and tertiary institutions as students commence study. Further research is needed to better understand the interrelatedness and specific relationships between these variables.