Individuals with SMI often have co-occurring substance use disorders, including co-occurring stimulant use disorder. This can create confusion when people present for care, as their psychotic symptoms may be related to their recent substance use, or their underlying mental illness, or a combination of both. Very often treatment for co-occurring conditions is not as easily accessible, and practitioners need to have a better understanding of the impacts of stimulant use on individuals with mental illness and how best to treat these issues simultaneously. Furthermore, when an individual is using one substance, they may also be using other substances, which can also make treatment and diagnosis challenging. People with SMI and co-occurring substance use disorders can present with other confounding issues including aggression or behavior associated with criminal conduct. They may be seen in forensic, carceral and emergency department settings as their care is often disrupted across multiple systems. This webinar will provide information about serious mental illness and co-occurring stimulant use disorder and its impact on clinical presentations and ways to address these issues.