Meh.
Definitely an extreme case. As Cleckley wrote in Mask of Sanity:
"The psychopath shows a striking inability to follow any sort of life plan consistently, whether it be one regarded as good or evil. He does not maintain an effort toward any far goal at all. This is entirely applicable to the full psychopath. On the contrary, he seems to go out of his way to make a failure of life. By some incomprehensible and untempting piece of folly or buffoonery, he eventually cuts short any activity in which he is succeeding, no matter whether it is crime or honest endeavor. At the behest of trivial impulses he repeatedly addresses himself directly to folly."
That sort of behavior can definitely cause some problems. There are some psychopaths with a bit more maliciousness in their personality...still, Kevin was a pretty extreme example.
It was alright. I seen it a long time ago...a bit slow-moving, but not horribly so if you enjoy drama films. I don't feel like I really got much out of the movie. However, it was interesting to see a portrayal of the difficulties of raising an unapologetically sadistic and psychopathic kid with emotional problems. I don't see myself watching it again, but it was entertaining for the time.