Is oppositional defiance disorder real or is it just a sign of a lack of discipline at home?

Real. Oppositional defiance disorder (odd) is a difficult to manage behavior disorder which has a biologic cause. Severe discipline or lax discipline may worsen the behavior; you may need some advanced parenting skills to manage the behavior. The majority of children with odd also have adhd. Your doctor can recommend a behavior specialist to help you develop a workable behavior plan.
ODD is real, complex. Odd (oppositional defiant disorder) is real, usually present before 8 years of age, more common in boys before puberty. Odd is more common in families with marital discord and with parent (s) with odd, conduct disorder, adhd, or mood disorders. Multiple etiologic factors have been suggested.