The sequence of drug use initiation is thus the essence of the GH. Accordingly, it is drug use itself that is viewed as the cause of drug use development. Likewise, the “stages” are defined in a circular manner: a stage is said to be reached when a certain drug(s) is used, but this drug is supposed to be used only upon reaching this stage. In other words, the stage both is identified by the drug and identifies that drug. In effect, the drug is identical to the stage (“marihuana is a crucial stage . . .”) (Kandel, 1975). There is no process or organismic characteristic, separate from drug use per se, which is presumed to cause or underlie the supposed developmental staging indicated by, and identical to, drug milestones. Moreover, the notion of “stage” itself is redefined from its common meaning, such that the later stages are assumed to be reachable, albeit less frequently, before the earlier ones. This renders the GH incongruent with the conventional biological developmental framework (cf. stages of embryonic development).
