Antisocial personality disorder (APD) is a condition in which people disregard the rights of others and violate those rights by acting in aggressive, irritating, and even criminal ways. APD begins in childhood and early adolescence. People with APD engage in bullying, vandalism, violence, and lying, and they do not feel guilt or regret for their actions. Two-thirds of those diagnosed with APD are male.

The causes of APD are not known, but low levels of serotonin, a brain chemical, may be one factor. Problems with the functioning of dopamine, another brain chemical, may also play a role. APD patients often have antisocial relatives, with substance abuse, divorce, and child abuse common in the family.

A large percentage of alcohol and drug abusers suffer from APD. For some, the abuse of alcohol or drugs causes the antisocial behaviors. For other abusers, substance abuse is just one expression...