indigenous populations in canada are at higher risk of adverse childhood experiences (aces; e.g., abuse, neglect, or other household challenges before the age of 18) when compared to non-indigenous populations. as the number of aces increase, so do rates of substance use and suicide risk. in non-indigenous populations, the presence of prior suicide-related behaviours (srbs) signals a need for higher intensity services within substance use treatment. this thesis sought to better understand the relationship between aces and srbs specifically amongst indigenous clients undergoing substance use treatment to better inform treatment planning. the first study of this thesis analyzes previously gathered data from a community-based participatory research program at an adult residential substance use treatment facility for indigenous people, while the second study of this thesis analyzes new data from culturally-validated srb measures incorporated into the same research program. in both studies, clients with longstanding mental health and addictions difficulties were invited to complete two surveys during the five week culturally informed treatment program. the first survey was administered at the beginning of the program and measured substance use and srbs, while the second survey was administered at the midpoint of the program and measured aces. [...]