Antisocial personality disorder (ASPD) is characterized by disregard for others and failure to conform to social norms. People with ASPD often behave impulsively and aggressively and lack remorse for their harmful actions. While symptoms typically emerge by age 15, a diagnosis requires symptoms be present by age 18. Treatments focus on enhancing thinking skills, but more research is needed due to challenges in diagnosing and treating ASPD.