Both genetic and environmental factors (eg, abuse during childhood) contribute to the development of antisocial personality disorder. A possible mechanism is impulsive aggression, related to abnormal serotonin transporter functioning. Disregard for the pain of others during early childhood has been linked to antisocial behavior during late adolescence.
Antisocial personality disorder is more common among 1st-degree relatives of patients with the disorder than among the general population. Risk of developing this disorder is increased in both adopted and biologic children of parents with the disorder.
If conduct disorder accompanied by attention-deficit/hyperactivity disorder develops before age 10 years, risk of developing antisocial personality disorder during adulthood is increased. Risk of conduct disorder evolving into antisocial personality disorder may be increased when parents abuse or neglect the child or are inconsistent in discipline or in parenting style (eg, switching from warm and supportive to cold and critical).