“How is ODD treated in a child?”

Behavioral therapy is the main treatment for ODD.

Greetings, You'd probably have to opt for a family systems approach (i.e., parent management therapy) which trains parents/caregivers how to deal with recalcitrance and oppositional defiance in children. A friend of mine works at the Parent Management Training Institute ( www.parentmanagementtraininginstitute.com) which has some excellent programs you could enrol in. PMT should be accompanied with individual child therapy incorporating CBT or DBT interventions to disproportionately alter the ratio of negative and positive behaviors in favor of the latter. Good luck! Paul

See this link..
https://www.mayoclinic.org/diseases-conditions/oppositional-defiant-disorder/diagnosis-treatment/drc-20375837