This post is EXACTLY why many states are slowly legalizing MEDICAL marijuana, for cancer patients, MS victims, and severe chronic pain patients. There's a prescription drug called Marinol, which is a synthetic form of THC. As someone who's dealt with severe rheumatoid arthritis for 20+ years, I can tell you that pain mgmt. doctors stay away from it, because it has nasty psychedelic effects, with little pain relief. Marinol works great for chemo patients with bad nausea, but that's it.
What little LEGIT research has shown that the native plant has cannabinoid compounds that moderate the "psych" effects, while providing pain relief. Yet, there's a tremendous amount of ANECDOTAL, non-scientific evidence that shows that smoking marijuana DOES provide pain relief, without the physical dependency issues that plague opiates. Just about everyone on this forum knows that you can smoke a joint today, then not touch one for months/years, and have NO cravings for it, or withdrawal effects.
NOTE: I'm not making excuses for those who abuse said substances, but if there's something out there that will provide pain relief without the addiction/dependency issues of opiates, then we deserve further, scientific research.