The information was given to me by my directors, who are professors of psychology, and a dean of psychology, at Canadian universities. They also have their own private practice. We've discussed ad nauseam the issues relative to young people, crime, predisposition to violence, and criminal behaviour.
The comment has always come back that in their estimation and in their experience--and these are people who have been in that particular area of medical practice for decades--it takes a minimum of at least three years of intensive clinical intervention, which means at least once or twice a week, to be able to change the predisposition or be able to change the behaviour of that individual.