Medication errors and adverse drug events (ADE) are common in community settings including primary care, general practice, mental health services, and community pharmacy. This study focused on factors contributing to ADE, specifically in patients with mental illness receiving care in the community. Several factors were similar to those in other patient populations (e.g., workforce shortages) but some were also unique to this patient group, including lack of knowledge of psychotropic medications, difficultly in contacting and following up with patients, and diffusion of provider responsibility.