I think there may be some confusion out there that psychopathy is synonymous with ASPD when, in my opinion, they're closely related but wholly separate disorders. Dr. Robert Hare estimates up to 80% of criminals could be dx'd with ASPD but of those only 20% are also psychopathic. Those 20% though are responsible for more than 50% of crime, usually the most serious, which goes a long way in quantifying just how dangerous they have the potential to be.
For the next two months
only a conduct disorder dx prior to the age of 15 is necessary diagnostic criteria for ASPD only - this fact will be rendered moot as it is being dropped with the new version of the DSM-V. A therapeutic mental health practitioner could never, and would never, currently diagnose someone as a psychopath. By DSM definition and diagnostics, psychopathy isn't a mental health disorder (the DSM-V will combine antisocial with psychopathic though). It is a term and diagnosis widely accepted and recognized in forensic psychology and is often used in conjunction with evaluations required by the criminal justice system. Further, the only tests that can actually establish psychopathy itself are forensic - the PCL-R and the PPI-R - though standard assessments can certainly hint to the disorder by way of axis II-Cluster B primarily, such as the MMPI and MCMI. ASPD's (and please realize this is very generalized, not all ASPDs meet the following description) have a propensity for criminality, have problems with relationships, and often have unstable employment histories. While psychopaths can maintain long-term relationships, be in high-level positions in their careers, and go their entire lives without ever committing a crime. I consider ASPD to be explosive and impulsive while psychopaths tend to be more manipulatively abusive for their personal gain. ASPD=reactive; psychopathy=cunning.
There is known cure for either ASPD or psychopathy. However, while extremely resistant to treatment those with ASPD
can learn to at least modify their behavior with intense therapy whereas, imo, there is absolutely no recourse whatsoever for psychopathy. I also see very different sides to psychopathy which I've described elsewhere as 'good' and 'bad'. They're each potentially dangerous and extremely destructive in their own ways. Many psychopaths weigh in on the scale somewhere in the middle. The 'good' are the ones you just can't spot until your bank account's been drained, you've been left homeless, and your pets were dropped off at the humane society by the psychopath. The 'good' are often charming, well liked, and popular. Then there's another type that, upon first meeting, the hair on the back of your neck rises - you innately sense something is wrong. (Those sensitive to psychopaths may be better equipped to spot both 'types' and the many in between.) The latter are, in my estimation, often the most depraved and cruel. Almost pure sadism. They're almost palpably inhuman and have great difficulty blending into society.
I believe a lot of parents discount clearly psychopathic tendencies until and unless those traits surpass criminal and/or violent boundaries. Some parents justify manipulative, controlling or abusive behaviors in their own kids. First, a psychopath's family is also generally their first victim pool. Secondly, I think its human nature to want to believe in what I call Spoiled Brat Syndrome (aka problem child) before believing in anything quite so dark, depraved, and resistant to treatment as psychopathy. It really is very easy when you love a psychopath to come with
any viable alternative as an explanation for their behavior. What parent would want to be confronted with their child essentially being 'soulless'?
In terms of adolescent psychopathy I think many assume one is out setting fires and torturing all the neighbor's cats...and they certainly
can be...but generally I think they're more along the lines of Veruca Salt from Willy Wonka.

They're still in the process of honing their manipulative prowess, which is the primary trait and resource of psychopaths - they depend on it for survival alone, so they're more apt to be pushing boundaries constantly, be extremely selfish, thoughtless, impulsive, shallow, etc. The problem of course is that a lot of teens are like that too which feeds into a pattern of easily discounting such behaviors for parents of psychopaths. Until their child does something so egregious that it can't be whisked under a carpet...and sometimes, even then, the parent will remain firmly wrapped in denial. Psychopathic children and adolescents, like their adult counterparts, refuse to ever accept responsibility for their behaviors, are averse to reward vs. punishment many parents utilize for behavior modification, are prone to victim-mentalities in which part of their manipulation becomes painting their parents as abusive or controlling, or using other emotional manipulators such as threatening suicide - and parents often relent in their attempts to enforce restrictions and hold their psychopathic children and adolescents responsible for their behaviors. This, of course, only serves to teach a psychopathic youth how best to go about getting what they want.
All MOO