Going back a little to the opiates situation and medical marijuana, there are a lot of unknowns with opiates. My wife has Ehlers Danlos Syndrome, a connective tissue disorder which causes intractable pain. Wikipedia defines intractable pain as "a severe, constant pain that is not curable by any known means and which causes a bed or house-bound state and early death if not adequately treated, usually with opioids and/or interventional procedures." She was on very high doses of several opiates and was having myoclonic seizures (random convulsions of the limbs and sometimes an arched back) for which no cause could be found. For a normal person, these kinds of seizures would be no big deal. For someone with her condition, they cause her increased pain. We thought it was the drugs, but the doctors said "seizures are not a side effect of ____." When we took her off the drugs for other reasons, the seizures stopped and they have not returned. She also went from 178 to 146 lbs in the 9 months that have passed since she was on such high doses, all weight which she gained while she was on those medications. I believe she also developed a rare condition in which opiates actually cause hypersensitivity to pain, known as opiate-induced hyperalgesia. When she came off the meds, her pain did in fact decrease until she experienced new injuries as a result of the connective-tissue nature of her condition. Now she is back on opiates, but in lower doses. She has regular "interventions" such as nerve ablations and other anesthesic treatments which don't help - in fact anesthesia in general causes increased and debilitating pain for days following because of how it relaxes the soft tissues.
And in general, these medications are also simply not "safe." The risk is low, but if a metabolic anomaly occurs (if you get food poisoning, for example, and you end of vomiting and the acid and enzyme concentration in the stomach is altered resulting in unusual metabolising of your medications and possible loss of the medication during vomiting), they can cause sudden death even in long term users with no side effects as a suddenly much higher dose is rapidly metabolized. Furthermore, you just puked out your guts. Guess what - you lost that dose and its not safe to take another. If it's an immediate release, you're probably going to hurt even worse as you go through that stomach illness, and that's on top of the pain from retching.
Medical Marijuana, if it worked, would be a godsend. Many people with her condition report that it helps. Insurance not covering it is a major problem, and that will be the case until it is fully and properly legalized and approved for treatment of pain like hers. It would cost us over $500 just to get her a MMJ card, hundreds of dollars every month for doctors appointments to get prescriptions and maintain the card, plus the cost of MMJ is considerably higher than the street cost of MJ. Non-medical is not the same, however - different strains have different properties. Like opiates, those that are best for recreational use are not the best for treating pain. Even among MMJ, there are many strains that work differently for different people with different conditions to provide varying degrees of relief for each individual.
But MMJ is not the only war on drugs concern. There have been times when it took me upwards of 6 hours to find a pharmacy that could provide her prescription. Pharmacies have turned us away from fear of DEA enforcement. When we had to take her off cold turkey and she had to go through withdrawal, it was because she couldn't just go see another pain doctor for a little while - jumping between pain doctors can also trigger DEA enforcement and get you on a list which will make it impossible to be prescribed opiates again.
But it doesn't end there. This fear of addiction is unreasonable. Some people are prone to addiction - others can safely use opiates for years without ever becoming even slightly addicted. People confuse addiction with physical dependence. People don't want to take opiates out of fear put in them by the FDA and DEA which is unreasonable when you take into account the pain they are in. Some doctors overprescribe, and that's a problem. Others won't prescribe as they should because of fear or misunderstanding. Families want and convince their loved ones not to take medications they NEED out of fear and misunderstanding. Some people need to carefully organize their pills in a Mon-Fri style pill box to avoid accidentally overdosing, but if they leave their prescription bottles at home they could be handcuffed and imprisoned, in their disabled and pain-ridden state, due to ridiculous law enforcement policies and the laws themselves. And it's all a product of the war on drugs.
TL;DR The war on drugs is a major problem for people with chronic pain, and it affects them in ways most people don't even realize.