Types of Conduct Disorder: Childhood-Onset Type Any of the diagnostic criterions of Conduct Disorder began before the age of 10. Adolescent-Onset Type This is marked by the absence of any Conduct Disorder characteristics before the age of 10. There are also three distinguishable severities of Conduct Disorder, these are: Mild This form of Conduct Disorder is present if only the minimum symptoms are present and the conduct problems cause only minor harm to others. Moderate A moderate form of Conduct Disorder is when the conduct problems effect or harm others intermediately. Severe This is where the child demonstrates conduct behaviors that are excessive or cause significant harm to others.