1. Hand out opioids like candy. Everyone has pain now and then(backpain, dentist, etc), so everyone gets to try them.

2. People become habitual users and in some cases junkies.

3. Restrict the supply of OTC opioids, while continuing to lose the war on illegally supplied drugs.

4. Addicts and people looking to avoid getting dopesick look to heroin for its low-cost and relative abundance.

Now you have a major spike in heroin users. From what I've heard, a lot of people switch to heroin because it's available. They switch to shooting up because it's cost effective.

When you're high as a kite, sleeping in the street or being covered in shit really doesn't bother you. When you're obsessed with getting another fix, you tend to lower the priority of 'non-essential' activities like bathing or eating.

Note that not all addicts end up sleeping in gutters. I learned via a friend that there are many hidden addicts in society. There are professionals who shoot H just to maintain and avoid getting dope sick. I think the perceived lack of opportunities for low-skilled and older workers has contributed to a situation where many would rather get high and be homeless than struggle holding down a 9-5 just to go broke at their first health crisis.