Jan C. van Ours and Jenny Williams, "Cannabis Use and Mental Health 
Problems", Journal of Applied Econometrics, Vol. 26, No. 7, 2011, pp. 
1137-1156.

This research draws on information collected in the 2004 Australian 
National Drug Strategy Household Survey (NDSHS). The NDSHS is managed by 
the Australian Institute of Health and Welfare on behalf of the 
Commonwealth Department of Health and Ageing. It is designed to provide 
data on awareness, attitudes and behavior relating to licit and illicit 
drug use by the non-institutionalized civilian population in Australia. 
The sample used in the paper is composed of 4771 males and 6719 females 
aged 26-50 years old for whom we have complete data on mental health, 
cannabis use, and the other control variables.

The 2004 NDSHS is a restricted dataset but available through the 
Australian Social Science Data Archive

  http://assda.anu.edu.au/data.html

To get access to the dataset, researchers have to: (1) Register online 
with ASSDA, (2) Complete a user undertaking form, (3) Apply to access a 
restricted dataset.

Note that a fee of $1,000 to use the 2004 NDHDS may apply.