Clonidine has been widely used in child and adolescent psychiatry, especially in attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), which are recently categorized under neurodevelopmental disorders. However, it is not recommended as a first-line medication for treatment, and current data on the use of clonidine are limited. Herein, we present 3 cases with ADHD and ASD comorbidity, if any, as well as other neurodevelopmental disorders, including intellectual…