Attention deficit hyperactivity disorder (ADHD) is notably overrepresented in substance use treatment centers, with an estimated prevalence of 21-23% when screening practices are implemented. Many adults in these settings receive an ADHD diagnosis for the first time, highlighting the frequent underdiagnosis of ADHD among individuals seeking treatment for alcohol and substance use issues. Additionally, those entering treatment programs represent only a small fraction of the broader population with problematic alcohol use. This review explores the research on the prevalence and treatment of co-occurring ADHD and substance use disorders (SUD), with a particular emphasis on alcohol use disorders (AUD) as the most common SUD. It also provides clinical guidelines for the screening and diagnosis of ADHD in patients with active alcohol and substance use and offers recommendations to enhance screening practices and improve access to treatment for individuals with co-occurring ADHD and AUD.