intergenerational trauma among indigenous peoples in canada is identified as an ongoing detrimental outcome of canadian colonialism. both adverse childhood experiences (aces) and substance use problems appear to be difficulties perpetuating intergenerational trauma among this population. while it is known that aces increase risk for a multitude of poor mental and physical health outcomes, the underlying mechanisms are less clear. executive functions (efs) may be one plausible mechanism linking aces to substance use difficulties, as efs are both affected by chronic stress during childhood and are associated with poor outcomes later in life. this community-based research project was driven by indigenous partnership who wanted to better understand how aces are implicated in the substance use difficulties their clients are facing. with this in mind, the goal of this study was to examine the interrelationships between aces, ef, and substance use outcomes among clients at an indigenous substance use treatment program in northwestern ontario. to do this, 80 participants completed self-report questionnaires at two time points while in treatment. [...]