Medicinal Cannabis Sir: There is no agreed definition of medicinal cannabis. The term is used to refer to the therapeutic use of herbal cannabis and its constituents. There are about 100 cannabinoids and other compounds at present, of which psychotropic tetrahydrocannabinol and nonpsychotropic cannabidiol have been the most studied. In the July-August edition, Professor Whitehall correctly discusses the multiple problems that can and do occur when cannabinoids are promoted for the management of ADHD. Similar difficulties are present in assessing the value of cannabinoids for many of the other conditions for which they are now being promoted. Most of this…