To the Editor: Australian and international evidence clearly demonstrates that controlling availability is one of the most effective means of reducing alcohol-related harm.1 In recognition of this, additional restrictions on availability have been introduced as part of both the Australian government’s Northern Territory Emergency Response (NTER) and the NT government’s Alcohol Management Plans.2 However, it has been widely asserted in public debate — particularly by those opposed to them — that these restrictions have had the unintended consequence of diverting people in remote communities from alcohol to cannabis consumption and that, as a consequence, there is an epidemic of cannabis use in remote communities.3
Generally, the international evidence is limited but indicates that the substitution of one drug for another is variable and complex, and not a simple one-to-one phenomenon.4 More specifically, there is a paucity of empirical data which could directly verify the assertion that cannabis has been substituted for alcohol as a consequence of the additional alcohol restrictions in the NT. However, while there may well have been some substitution, the increase in cannabis consumption was occurring before the NTER and NT government restrictions. In 2004, Clough and colleagues reported an increase in cannabis use in Arnhem Land (NT).5 Furthermore, in 2006, Putt and Delahunty reported an increase in Queensland, Western Australia and South Australia — jurisdictions that were not later subject to the NT restrictions.6
Thus, while there may have been some substitution of cannabis for alcohol following introduction of the NTER restrictions and Alcohol Management Plans, it seems clear that the increase in use of cannabis cannot be attributed primarily to these interventions. The problem, regardless of the cause, needs to be addressed, but it will not be addressed simply by relaxing alcohol restrictions.