The effects of the cannabis Expiation Notice system on the prevalence of cannabis use in South Australia: evidence from the National Drug Strategy Household Surveys 1985-95

FRANÇAIS :
En 1987, l'Australie a assouplit sa législation sur le cannabis en ne réprimant plus la possession de petites quantités pour usage personnel, mais en donnant simplement une contravention. Par contre, la culture et le trafic ont été sévèrement punis. L'impact de ces mesures a été évalué par estimation de la variation de la consommation entre 1985 et 1995, pour les indicateurs d'usage au cours de la vie, d'usage courant, de sexe et âge, entre l'Australie du Sud et les autres régions. La prévalence de l'usage au cours de la vie a augmenté de 26 à 36% au Sud mais également en Tasmanie, à Victoria et en Nouvelle Galle du Sud, même si l'écart le plus grand concerne le Sud. Par contre il n'y a pas de différence en ce qui concerne l'augmentation de l'usage hebdomadaire entre les régions. Il ne semblerait donc pas que le changement de législation soit responsable d'une augmentation de la consommation de cannabis en Australie du Sud.
ENGLISH :
This study sought to examine the impact of the Cannabis Expiation Notice (CEN) scheme on the prevalence of lifetime and weekly cannabis use in South Australia. Data from five National Drug Strategy Household Surveys between 1985 and 1995 were examined to test for differences in trends in self-reported: (1) lifetime cannabis use; and (2) current weekly cannabis use, after controlling for age and gender, between South Australia and the other states and territories. Between 1985 and 1995, rates of lifetime cannabis use increased in SA from 26% to 36%. There were also significant increases in Victoria (from 26% to 32%), Tasmania (from 2 1% to 33%) and New South Wales (from 26% to 33%). The increase in South Australia was significantly greater than the average increase throughout the rest of Australia, but the other Australian states differed in their rates of change. Victoria and Tasmania had similar rates of increase to South Australia; New South Wales, Queensland and Western Australia showed lower rates of increase; and the Northern Territory and the Australian Capital Territory had high rates that did not change during the period. There was no statistically significant difference between SA and the rest of Australia in the rate of increase in weekly cannabis use. While there was a greater increase in self-reported lifetime cannabis use in South Australia between 1985 and 1995 than in the average of the other Australian jurisdictions it is unlikely that this increase is due to the CEN system, because similar increases occurred in Tasmania and Victoria (where there was no change in the legal status of cannabis use), and there was no increase in the rate of weekly cannabis use in South Australia over the same period. (Author's abstract.)