Conduct disorder is a behavioral and emotional disorder in children and teens characterized by disruptive and violent behavior as well as problems following rules. It is categorized based on when symptoms first appear - childhood onset before age 10, adolescent onset during teenage years, or unspecified onset. Symptoms include aggressive behavior toward others or animals, deceitfulness like lying and stealing, destructive behavior such as arson, and violating rules by skipping school or substance abuse. Conduct disorder is caused by genetic and biological factors as well as psychosocial influences like child abuse, family dysfunction, or poverty. Those at highest risk are males, those living in poverty or urban areas, and those with a family history of mental illness or conduct disorder. Treatment involves medication, psychotherapy,