The disturbance must have occurred for at least six months and must demonstrate at least three of 13 symptoms which include such things as stealing without confrontation of the victim, running away from home overnight, often lying, engaging in fire setting, being truant from school, breaking into someone's house or car, destroying other people's property, being physically cruel toward animals, forcing someone into sexual activity, or using a weapon in more than one fight, initiating fights, stealing with confrontation of the victim, and being physically cruel to people. There is no lower limit to the age at which this could be diagnosed and the upper limit is vague. In other words, the DSM III-R criteria seemed to label those children with Conduct Disorder whom experienced clinicians would agree have this. There has been a six fold increase within the last 10 years, especially with girls, for reasons that are not entirely clear. Violence and diagnosis of CDO is found more commonly in those in the socioeconomic underclass as well as minorities.
Violence is much more common in the U.S. than Western Europe.
A number of studies done including those done at the Medical College of Virginia have suggested that there is no overall difference in the prevalence of diagnoses found in children in state mental hospitals versus those in detention except that minorities are more likely to be routed into the juvinile justice system rather than treatment. The etiology of CDO is likely multi-factorial. It is well known that there is an increased frequency of diagnosis with parental unemployment, over crowded housing, large families, broken homes, marital discord, families who have had a death of a family member, and a socially isolated family. DSM III-R lists parental rejection, inconsistent management with household discipline and early institutional living as risk factors. It has been felt that this sub-type may have a better prognosis.