What is the most likely diagnosis for a 16-year-old boy who exhibits defiant behavior and has legal issues for stealing?

The most likely diagnosis for the 16-year-old boy exhibiting defiant behavior and legal issues related to stealing is conduct disorder. This diagnosis is characterized by a pattern of disruptive and violent behaviors that violate societal norms and the rights of others. In adolescence, such behaviors may include theft, lying, and aggression, which appear to be consistent with the boy's actions.

Conduct disorder is typically diagnosed when an individual displays a range of behaviors that not only disrupt their own development but also negatively impact their social interactions and functioning. The presence of legal issues for stealing indicates a more severe level of transgression that aligns more closely with conduct disorder rather than other disorders listed.

To contrast with the other options, attention-deficit hyperactivity disorder (ADHD) primarily involves inattention, hyperactivity, and impulsivity, but does not specifically include the aggressive or harmful behaviors seen in this case. Intermittent explosive disorder involves recurrent episodes of impulsive aggression that are disproportionate to the situation but typically does not involve a pattern of rule-breaking like stealing. Oppositional defiant disorder is characterized by a pattern of angry, irritable mood, argumentative behavior, and defiance but does not usually include the more severe antisocial behaviors and legal issues related to conduct that are seen