About 10.2% of people have or have had ODD (11.2% of males and 9.2% of females). In many cases this condition worsens into conduct disorder, which often worsens into antisocial personality disorder. This is more likely in boys than girls, and more likely if the person also has attention-deficit hyperactivity disorder. ODD typically begins in childhood. It is the most common mental disorder in children. It is unusual in adults, because the affected person usually either recovers or develops ASPD. 