Many veterans carry the invisible wounds of war. For some, these wounds manifest as mental health challenges; for others, they lead to substance use as a way to cope with the burdens of service. Often, these struggles are intertwined, with one exacerbating the other. According to recent data, approximately 1.1 million veterans are affected by both substance use disorder and mental illness. This book explores how we can improve access to effective, quality care for veterans dealing with substance use disorders and mental health conditions. It aims to highlight the interconnectedness of these issues and examine comprehensive strategies to better support veterans on their path to recovery.