Behavior is a product of thinking. This is absolutely fundamental. What is termed "behavior modification" cannot occur in a lasting manner unless thinking changes. One could argue that if one behaves differently, thinking may change later. However, in order to behave differently in the first place, a thought process must occur initiates the behavioral change.
While helping offenders change, it is certainly helpful to offer them opportunities to learn new skills and further their education. However, the outcome of such measures alone will invariably be a criminal with job skills, rather than one without. And he may even use his new job skills to gain entre into new arenas to commit crimes. Improving one's education can be extremely valuable not only as a means to an end (e.g., a better job), but it is worthwhile in itself. But it by no means ensures responsible functioning. I recall a criminal who could quote Plato and Aristotle but failed to acquire the concepts of how to live responsibly that most fourth graders have.
Drug treatment programs, unless they include a cognitive component, are insufficient in terms of a person living responsibly.
Education as to the effects of drug abuse and abstinence are critically important. However, it is essential to examine what is basic -- the way the individual was thinking even before he started using mind-altering substances.
For people who live responsibly, the same principle holds. To change something about themselves, they must become aware of their thinking, grow fed up with that thinking (and its consequences), deter old patterns thoughts, and substitute corrective thought patterns.