Cannabis drugs are obtained from the unfertilized flowering tops and the leaves of the plant, which can be grown in climates varying from temperate to tropical. The potency does not differ as between these groups, provided that the conditions in which they are grown are the same. To yield a potent drug a high temperature and low humidity are necessary, and these conditions are seldom available naturally in the United Kingdom. The Anglo-Saxon countries also have an extensive and continually changing vocabulary.
Cannabis contains a number of identifiable constituents.
A detailed description of the pharmacology of cannabis is given in Appendix 5. Clinical Features 22. This digest reflects the experience of a number of different cultures. In Section III we try to relate United Kingdom experience to this picture. The effects of drugs which act upon the central nervous system are not determined solely by the drug and its dose.