I have used this for years 8,9,10 and found it very suitable as ours is a 'special' school for EBD, most pupils have very short attention span. The wording and diagrams appeal to the puils in all age ranges.
Too many drugs resources try to moralise, and that just won't wash with kids today especially at KS4. This has become my core drugs resource because it treats the students as intelligent beings capable of making their own decisions if suitably informed.