Cannabis use, a stepping stone to other drugs?

The case of Amsterdam
Peter Cohen & Arjan Sas
In: Lorenz Böllinger (1997), Cannabis Science / Cannabis Wissenschaft. From prohibition to human right / Von der Prohibition zum Recht auf Genuß. Frankfurt am Main: Peter Lang Eurpaïscher Verlag der Wissenschaften. pp. 49-82.

publicationDoes smoking reefer lead to using other drugs, in daily practice usually described as cocaine and heroin? Raising the possibility that the answer to this question might be affirmative, is known as the stepping stone hypothesis. Recently this hypothesis has been raised again in slightly other terms: cannabis use as a “gateway” to other allegedly more dangerous drugs.

application-pdfDownload the article (PDF)


In Amsterdam, the access to cannabis type drugs developed from highly suppressed to almost universal and hassle free in the period between 1965 and 1980. We tested the theory that cannabis use will - almost automatically - result in (heavy) use of other drugs. Indeed, we found among almost 9,000 respondents out of 2 large household surveys in 1990 and 1994, that in Amsterdam cannabis use is an almost necessary condition for developing other drug use. However, most cannabis users in Amsterdam (75%) do not report other drug use. Also the ‘never cannabis users’ in Amsterdam do not consume other illicit drugs. Curiosity inasmuch as it develops in cannabis users to use other drugs is confined to cocaine and ecstasy, while heroin is almost excluded.

In order to test the ‘stepping stone hypothesis’ we formulated a testable series of such hypotheses, varying the terms but keeping the criterion stable. We arbitrarily stated that any of our stepping stone hypotheses would be confirmed if we could find 75% of the cannabis users to behave according to the hypothesis. None of the stepping stone hypotheses could be confirmed although data that approached confirmation could be found for a minority of users with the highest levels of cannabis involvement. Some statistical / epidemiological evidence for a stepping stone phenomenon that associates cannabis use to some type of use of other drugs is available for a small minority of cannabis users only.

Apparently, in Amsterdam where use of illicit drugs is made possible due to of hassle free (illicit) availability of that type of drug, the use of cannabis satisfies almost all curiosity. Small numbers of experienced cannabis users try other illicit substances, mostly cocaine and ecstasy. This is true for cannabis users who never experienced active law enforcement against individual drug use (the ‘young’ age cohort born in 1985 or later) as well as for cannabis users who were raised during the then existing regime of active law enforcement against cannabis and other individual drug use (the ‘old’ age cohort born before 1958). We confirmed that, if it occurs, other drug use always succeeds use of cannabis. We did not try to explain why this is so, nor why the large majority of cannabis users do not develop curiosity to use other drugs.