For which disorder is impulsivity and aggression evident from a young age, specifically before the age of 18?

The presence of impulsivity and aggression from a young age, particularly before the age of 18, is a hallmark characteristic of Conduct Disorder. This disorder is primarily diagnosed in children and adolescents and is characterized by a persistent pattern of behavior that violates societal norms and the rights of others. Individuals with Conduct Disorder may display behaviors such as aggression toward people and animals, destruction of property, deceitfulness, or serious rules violations.

The early onset of these behaviors is significant in establishing the diagnosis and understanding the trajectory of the disorder, which may lead into more severe issues in adulthood if not addressed. The anticipation of aggressive or impulsive behaviors and their continuous occurrence in various settings—in school, at home, or in social interactions—draws attention to the disorder's impact and the need for early intervention strategies.

In contrast, the other disorders mentioned do not specifically feature the early manifestations of impulsivity and aggression as core symptoms or, if they do, are not focused on in the same way as Conduct Disorder. For example, personality disorders typically manifest in late adolescence to early adulthood; obsessive-compulsive disorder revolves more around intrusive thoughts and ritualistic behaviors rather than impulsivity; and social anxiety disorder is characterized by intense fear in social situations, not impulsivity or aggression.