This chapter examines the complexities of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), highlighting their overlapping symptoms and unique characteristics. The evolving diagnostic criteria and the significant change brought by the DSM-5 in 2013, which allowed for the comorbid diagnosis of ASD and ADHD, are emphasized. This change has important implications for treatment, particularly for under-recognized and minoritized populations who face diagnostic disparities. The chapter also discusses the necessity of a nuanced approach in differentiating between ADHD and autism, considering their shared challenges in self-regulation, attention, and social skills. The importance of collaborative partnerships with educators and therapists is underscored to ensure comprehensive, patient-centered care.