Australian secondary school students' use of tobacco, alcohol, and over-the-counter and illicit substances in 2011
5.12 Use of any illicit substance excluding cannabis
Because the use of cannabis was more prevalent than any other illicit substance, trends in its use tend to drive trends in the use of ‘any illicit substance’. For this reason, the above analyses were repeated using an index of illicit substance use that excluded cannabis. The proportion of students who had used any illicit drug other than cannabis in their lifetime or in the prior month in 2005, 2008 and 2011 are also shown in Table 5.22.
The proportion of students using any illicit drug other than cannabis was lower than when the index of drug use included cannabis.
The proportion of 12- to 15-year-olds who had used any illicit substance other than cannabis in their lifetime decreased significantly between 2005 and 2011 (p<0.01) but did not change between 2008 and 2011. The proportion of 12- to 15-year-olds using an illicit substance other than cannabis in the past month in 2011 was not significantly different from the proportions found in 2008 or 2005.
Among 16- and 17-year-olds, the proportion using an illicit substance other than cannabis in their lifetime in 2011 was significantly lower than the proportion found in 2005 (p<0.01), but not 2008. There was no change in the proportion of all 16- and 17-year-old students who had used illicit substances other than cannabis in the month before the survey between 2005 and 2011, or between 2008 and 2011.