By definition, antisocial personality disorder, or ASP, is a lifelong personality disorder that affects many more men than women and begins before age 15. The disorder is chronic, though it tends to be worse early in its course. The disorder peaks during the late teens and early 20s.
In their 40s and 50s, about half the people with ASP are either improved or in remission. Age 35 is the average age that improvement is likely to be seen in terms of a reduction in dangerous and destructive behavior. Researchers say, however, that improvement can come at any age.

Even with improvement, people with ASP are not always trouble-free. They may no longer be a threat to the life and property of others, but they experience continued interpersonal difficulties and hostility toward others. When improvement or remission occurs, it typically comes after years of antisocial behavior that has stunted the person’s educational and work achievement. It is unlikely that antisocial people can ever completely overcome these “lost years,” which explains why they continue to have low socioeconomic status.

Some antisocials, mostly men, have antisocial problems early in life, which develop into more serious behavioral problems. But the majority of antisocial youth develop a less severe behavior disorder that is usually limited to their teen years. For these youth, behaviors typically occur in the context of peer group pressure. These teens have little or no history of earlier antisocial behavior and tend to spontaneously improve, explaining why most children with conduct disorder never develop adult ASP. In fact, only 25 percent to 40 percent of children with a conduct disorder develop ASP.