It has long been recognized that users of illegal drugs may be difficult to identify, let alone recruit into a study . That chronic users of cannabis would seek medical evaluations and be so willing to share sensitive personal information within the context of their required evaluations was the unanticipated benefit of Proposition 215 that made this study possible.
Birth cohort analysis of the average ages at which applicants reported first trying alcohol, tobacco and cannabis (Table 8, Figure 1) demonstrates that a surge in youthful marijuana use began in the US in the mid Sixties. However, that event was not documented until publication of the first Monitoring the Future (MTF) data in 1975 demonstrated that over half of American adolescents were trying marijuana while still in High School .
Close questioning of applicants suggests that the majority had been motivated by a mix of physical and emotional symptoms which had been experienced at varying times in their lives. Further, that a majority had become initiates, and later chronic users of cannabis under circumstances that suggest that it was for relief of emotional symptoms in most instances. Their discovery (usually later), that cannabis also relieved physical symptoms, was most frequently made within a context of established chronic use. That notion is further supported by recent literature indicating that phytocannabinoids, newly discovered endocannabinoids, and synthetic cannabinoid agonists all seem to manifest anxiolytic effects in both humans and animals [4–8].
More than 85% of applicants had tried other illegal drugs, principally lysergic acid diethylamide (LSD), psilocybin, cocaine, and/or MDMA. The majority of those doing so hadn't remained chronic users of any except cannabis. While a majority have continued to use alcohol occasionally, the volumes consumed and the occurrence of events related to alcohol excess have sharply diminished.
A "gateway" hypothesis had developed from observations  that most marijuana users studied in the early Seventies were adolescents and young adults who had first tried alcohol and tobacco; also that many had tried marijuana before later trying heroin. However, subsequent efforts to establish a definitive causal link between marijuana and "harder" drugs have been largely unsuccessful . More recently, a theoretical alternative was shown to provide an explanation for accumulated MTF data that is at least as coherent .
A significant percentage of male applicants under 30 had been treated or evaluated for treatment with Ritalin or other stimulants for attention deficit hyperactivity disorder (ADHD) as children and their histories of a preference for morning use of minimal amounts strongly suggest that inhaled cannabis enhances their ability to concentrate. The statement of one, a construction company estimator, was revealing: "after two hits (of marijuana), and my morning coffee I'm the best estimator in the company." Another, a dental technician, stated that, when I first look at my workbench, I think I'll never finish, but after a couple of tokes (of marijuana), I'm through (with work) by two o'clock." Thus, reduction of work related anxiety seems a major factor in deciding to apply for legalized use of cannabis.