THE GLASS CEILING ON EVIDENCE OF CANNABIS RELATED HARMS – FLAWED OR JUST FALSE?

The authors rightly warn against generalizing findings from clinical samples to the whole population of cannabis users. We have considerable difficulties in determining how large is the proportion of users seeking treatment to the total population of users. This problem is not entirely unique to the drug field; similarly, a large majority of alcohol-dependent people also do not seek treatment. In an attempt to get closer to the truth, various methods to estimate the prevalence of illicit drug use were triangulated in a Swedish project [2]. The main study was a large general population survey, which was combined with surveys of high-risk groups, a respondent-driven sampling study and register-based methods. Survey data, with a 52% response rate, indicated that 127 000 Swedes were regular drug users. Register data from the patient register and from the Prison and Probation Services estimated 29 500 as problematic drug users. This means that there is a large hidden population of people with regular drug use, but where this is not identified in the health or corrections systems. One part of this hidden population consists of drug users who do not experience difficulties and therefore do not seek treatment. It is also clear, however, that we have another group of users who experience severe problems but nevertheless refuse to seek treatment. A number of reasons may explain this, but one with special significance in the addictions field is the stigma attached to drug use. This stigma also permeates most treatment facilities, including staff attitudes, labelling, etc., making treatment unappealing to many of those in need of it. Drug users who do seek treatment for various complications to drug use, e.g. depression and infections, tend not to volunteer information about their drug use and, in the majority of cases, are not asked about drug use. In most of these treatment episodes, drug use or diagnoses of harmful use or dependence are not recorded. This gives rise to a number of methodological difficulties. Based on the available data it is, for instance, difficult to determine whether there is an epidemiological paradox within the drug field of the same nature as within the alcohol field. In the alcohol field it is clear that most problems and costs arise within the larger group of heavy drinkers that do not belong to the most severe group [3–5]. It seems reasonable to assume that the same principles would apply within the drug field, but the lack of data does not allow any firm conclusions. This has important policy implications: are we only seeing the tip of the iceberg in the drug field—or are we seeing most of the problem?