First order crimes. For example drinking, then getting in a crash would be a first order crime of alcohol use.
A second order crime could be something like stealing money to buy your next beer, or running an illegal bootlegging operation.
In deciding how to police the issue, the last thing you want to consider is punishment, and the first you want to consider is harm reduction.
Going after dealers just doesn't fucking work. We've been spending billions on it, and in doing so we have a non-stop line of dealers and manufactures making more deadly and addictive concoctions every day. The more you bust the dealers, the more the price goes up, the more stealing occurs by the users, the and more corruption of law enforcement by the dealers paying people off because of the huge sums of money involved happen. As they say "There was a war on drugs, drugs won".