KAS 5a. For preschool-aged children (age 4 years to the 6th birthday) with ADHD, the primary care clinician should prescribe evidence-based parent training in behavior management (PTBM) and/or behavioral classroom interventions as the first line of treatment, if available. Methylphenidate may be considered if these behavioral interventions do not provide significant improvement and there is moderate to severe continued disturbance in the 4- through 5-year-old child’s functioning. In areas where evidence-based behavioral treatments are not available, the clinician needs to weigh the risks of starting medication before the age of 6 years against the harm of delaying treatment.