This is unfortunately very true. Many physicians, unless educated by personal experience, don't appreciate the debilitating affect chronic pain has especially when untreated or undertreated.
They appreciate it fine. They just don't want the DEA SWAT boys busting in their door, machine guns pointed in their faces, and in their family's faces, and then forced to serve twenty years in Federal Prison for merely exercising their best medical judgment. And, no, proving that your prescription was based on your medical school training in standard practice is not a permitted defense when the Feds have placed a target on your back.
