Suicide Kings has a very nice depiction of a young morphine junkie played by Jeremy Sisto. Toward the beginning of the film there is a scene showing this character shooting up. The reason this scene was put into the movie, according to the director, was to show that this character might be the "inside player". For other characters, great lengths were gone to in order to show that they had some motivation to be such a snake. One character, for example, had lost $20,000 gambling. The motivation for the junkie was shown in one ten second scene shooting up.
This logic comes from the fact that heroin addicts pay a lot of money for heroin. This character is a medical student, however. And he is clearly stealing the drugs, not buying them. So it doesn't make sense that he would need large sums of money. Large sums of money would probably not help him--he's a rich boy who wouldn't know where to go to score drugs.
It is unfortunate to see opiate users stereotyped, but besides this one (important) aspect, this character is mostly not stereotyped. He is the most reasonable of the young characters: thoughtful and caring. In the end, he is the most likeable character as well. The first battle that must be won against the War on Drugs is the identification battle: the population as a whole must see drug users not just as humans but as capable and complex humans. Movies like Suicide Kings give hope.