Conduct disorder is a mental health condition that starts in childhood or teenage years (usually between 6 and 15). It involves a pattern of serious rule-breaking and harming others. Understanding this disorder is important because it is linked to more severe criminal behavior later in life, both as teenagers and adults. 

Signs of conduct disorder include 

• Disruptive or harmful behaviours that last for several months and happens frequently 

• Aggressive behaviour towards others (including animals) 

• Destruction of property on purpose 

• Lying to avoid responsibility or to get a desired outcome or object 

• Serious rule breaking 

• Stealing