Why does the FDA continue to claim cannabis has no medicinal qualities, yet the Federal Govt.owns US

Because of the recent and widespread attacks upon the medicinal cannabis movement across this nation, and to have Congress explain just exactly why the FDA refuses to reclassify cannabis from a schedule 1 to a Schedule 2 or 3, allowing physicians to finally prescribe cannabis to those who so desperately need it the most, without fear of arrest or incarceration. The FDA continues to claim that Cannabis has no medicinal qualities whatsoever, and yet the US Federal Govt. owns US Patent Number 6,330,507, which unequivocally states that cannabinoids are useful as treatments for a myriad of disease states, such as auto-immune disorders, anti-inflammatory diseases, as well as a being a neuroprotectant. I hope for this conflicting information to be brought up for discussion, and to have the Congress to explain to the People why the FDA claims cannabis has no usefulness medicinally, while the Federal Govt. itself not only owns a Patent for these cannabinoids, but goes on to state just exactly how useful they are in the treatment of a wide variety of human ailments. They can't have it both ways, and millions of seriously and terminally ill Americans are tired of Congressional inaction on this issue...