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Cohen, P.D.A., H. Kaal (2001), Penal policy has little to no influence on the use patterns of experienced cannabis users, Press release October 25 2001.
© Copyright 2001 CEDRO Centre for Drugresearch, University of Amsterdam. All rights reserved.

[Report: The Irrelevance of Drug Policy][Dutch]

Penal policy has little to no influence on the use patterns of experienced cannabis users

Comparative study of cannabis use in Amsterdam, San Francisco and Bremen, by the Centre of Drug Research, University of Amsterdam

Cohen, P.D.A., H. Kaal

International comparative research in Amsterdam, San Francisco and Bremen suggests that penal policy with regard to the use of cannabis has little influence on the use patterns of experienced cannabis users. The samples do not reveal any substantial differences in intensity and circumstances of use. This is the main conclusion of the most recent report of the Centre for Drug Research (CEDRO) of the University of Amsterdam, in cooperation with the University of California and Universitšt Bremen.

Earlier research conducted by CEDRO in 1994 and 1995 was replicated with a high degree of comparability in San Francisco and Bremen in 1998 and 1999. A total of 536 experienced cannabis users were interviewed, divided over San Francisco (265), Amsterdam (216) and Bremen (55). Despite a number of shortcomings (the number of respondents in Bremen was relatively low, and there were some unavoidable problems in comparability) the study nevertheless gives unique insight in cannabis use of experienced users under different forms of cannabis policy. It can thus be considered a first step towards internationally comparative research on the effects of drug policy, providing rational and factual information for policy making.

The data show that the level of cannabis use in the three cities is very diverse: the percentage of adults between 18 and 70 years of age who have even used cannabis is 62% for San Francisco (figures 1998), 15% for Bremen (1998) and 34% in Amsterdam (1994). However, the use pattern of experienced users in the three cities were surprisingly similar on almost all variables measured. The ages on which they first started using cannabis (16/17 years), reached their period of top use (ca. 21 years) and quit using (ca. 34 years) were almost identical. They used similar quantities of cannabis with a similar frequency, provide the same types of reasons for their use and apply the same restrictions to their own use.

Part of daily life

The picture that the CEDRO study portrays is that cannabis use is part of the everyday life of the users ('normalisation'). Although users clearly make mention of the disadvantages of cannabis use - it makes you less active - they consider these to be outweighed by the advantages - relaxation. The most frequently occurring pattern is that of the user whose use initially increases until it reaches a certain level, and then gradually decreases, after which part of the users quits using altogether. This pattern can be seen with the frequency of use, the quantity of drug used and even in the level of high reached.

Most users restrict their use to evening and weekends, although after some time more users also consume cannabis during the week. Most cannabis users prefer to use in a social setting, with friends or acquaintances, when feeling good. Of the situation regarded as unsuitable for cannabis use, work is the most important. Most users who had quit using indicated they had done so simply because they no longer felt the need, often as a result of changes in their lifestyle. Only a small minority of those interviewed (6-9%) had ever considered to ask for help regarding their cannabis use.

Influence price and drug policy

The price of cannabis appears to have only a minor influence on the level of use, and also 'policy' had only little impact on the experience of the users. Although users in San Francisco and Bremen need slightly longer to obtain their cannabis than in Amsterdam, the majority felt they could get hold of a gram within less than half a day. The overwhelming majority of users felt it was unlikely that they would ever be arrested for possession of cannabis. Fear for arrest was higher in the other cities than it was in Amsterdam, but as the study showed, this had only a marginal impact on the experience and practice of the cannabis user.

The study, partially funded by the Dutch Ministry of Health, Welfare and Sport, is the result of cooperation of CEDRO with the University of California (Santa Cruz), Sociology Department, and the Universitšt Bremen, Fachbereich Rechtswissenschaft/BISDRO. Authors of the report are CEDRO researchers Dr. Peter Cohen and Dr. Hendrien Kaal.

Last update: February 9, 2010