A combination of common traits we find individually in many kids. Many children are arrogant, aggressive, prefer being physical with mates. Some kids are even short tempered with destructive nature. Some are undisciplined & few are there who have tendency to steal other's goods , be it a pencil or wrist watch. But if 3 or more such traits are present in any child for a considerable time, it's no more bad habits, it's a disorder, Conduct Disorder.
Conduct disorders are often more serious in consequences than oppositional defiant disorder because of violation of important societal norms & disregard of right of others. Aggressiveness causes harm to people or animal while non aggressiveness causes property damage, theft & rule violation. Even physical aggression is a predictor of later difficulties. Boys with higher childhood physical aggression are far more likely to be aggressive in later life.
Both ADHD & ODD are often associated with later development of conduct disorder in adolescence. Kids diagnosed with combined subtype of ADHD are more likely to develop conduct disorder than kids in inattentive subgroup. Children with CD are also likely to have other disorders. They are frequently diagnosed with some of internalizing behavior including withdrawn behavior, anxiety & depression. It's estimated that around 70% of children with CD also have one of these other diagnoses.
Rate of CD is much higher in families that are stressed by conflict & poverty & in which one or both parents have a psychiatric disorder, such as Anti Social Personality or Alcoholism. Several factors have been investigated to determine what specific factors put kids growing up in such a family at special risk. These include genetically influenced predisposition, lack of social & academic skills & parenting factors affected by other causes like financial hardship or unemployment.
Probably the most effective treatment for CD is prevention. Some other areas to focus are social skills, anger control, goal setting, parental training, booster sessions & collaboration with schools when needed.