Children between the ages of 6-12 years who are diagnosed with impulsive aggression comorbid with ADHD and have participated in the 810P301 or 810P302 study are invited to participate in this study. This is a Phase 3 open label extension (OLE) study with the objective of collecting long-term safety data on the use of SPN-810 in treating impulsive aggression in pediatric subjects with ADHD, when taken in conjunction with standard ADHD treatment. After confirmation of eligibility, all subjects will be treated with SPN-810.Subjects will be given a choice to extend participation in this study every 6 months for up to 36 months.