According to the Center for Disease and Control (2016), Behavior therapy is an effective treatment for attention-deficit/hyperactivity disorder (ADHD) that can improve a childs behavior, self-control, anger outburst, and self-esteem. It is most effective in young children when parents deliver it. Studies recommend that providers refer parents of children younger than 12 years old for training in behavior therapy. For children younger than six years old, parent training in behavior management should be utilized before prescribing ADHD medicine (CDC 2016) 
       A significant outcome is noted. When parents are trained in behavior therapy, they learn skills and strategies to help their child with ADHD succeed at school, at home, and in relationships. This process appeared very time consuming; however, that helps resolve some of the behavioral problems at home. 
The idea of home alone for a couple of hours with his child is not the best because anything can happen in a minute; his parent must find a way to fill in those hours of him being home alone. 
       Medicines are usually given to children or teens with ADHD, ODD, and DBD only if psychosocial treatment alone does not help enough. Medications are generally taken together with psychosocial treatment (Agency of Healthcare Research and Quality 2016)
       I am glad Depakote is helping him with his aggression, and using a case management program will also help manage treatment. Reward systems have been proven to be effective in changing behaviors. 
References,
Agency of Healthcare Research and Quality (2016) Treating Disruptive Behavior Disorders in Children and Teens. Retrieved from Treating Disruptive Behavior Disorders in Children and Teens | Effective Health Care Program (ahrq.gov)
Center for Disease and Control (2020) Parent Training in Behavior Management for ADHDA. Retrieved from Parent Training in Behavior Management for ADHD | CDC