One of the issues that makes drug policy complicated is the heterogenous nature of the user base.
The overwhelming majority of users are weekend recreational sorts, who may go off the deep end in times of stress, but are most at risk from drug-affected car accidents and the like.
Then there are the fast-burn junkies; usually mentally ill, often abuse survivors, frequently homeless, high risk of overdose and suicide.
Add to that another group of middle-aged habitual drinkers/smokers, whose primary risks are long-term health related.
The best policy for one group may not be the best policy for all groups. But we do know that blind prohibition is crap for all three.