National mental health report 2013

Indicator 8: Rates of use of licit and illicit drugs that contribute to mental illness in young people

Page last updated: 2013

Key messages:

  • Data from the National Drug Strategy Household Survey show that use of both licit and illicit drugs has decreased over time.
  • In 2001, 47% of 14-29 year olds engaged in risky drinking in the previous year. This had reduced to 42% by 2010, the lowest figure recorded to date.
  • In 1998, 36% of 14-29 year olds used cannabis. By 2010, this figure had halved (19%), although the latter figure represented a rise from 2007.
  • Ten per cent of 14-29 year olds used amphetamines in 1998 compared with 4% in 2010. As with alcohol, these are the lowest figures recorded to date.
Agreement to this indicator in the Fourth National Mental Health Plan reflected concern at the level of government and at the broader community level about substance abuse in young people and its perceived contribution to increased rates of mental illness and associated demand upon health services. While national programs have been initiated under the National Drug Strategy, further targeted efforts were acknowledged as necessary to reduce substance abuse, particularly the use of illicit drugs that may contribute to mental illness, and to deal with the challenge of providing services to people presenting with comorbid mental health and substance abuse problems.

Regular updates on the level of substance abuse in young people are provided through the National Drug Strategy Household Survey. This survey is conducted every three years by the Australian Institute of Health and Welfare, and provides insights into whether patterns of drug and alcohol misuse by young people have changed over time. Three substances of major priority are considered below, namely alcohol, cannabis and amphetamines. Usage rates for each of these drugs by younger people are of particular concern due to the mental health problems often associated with them. Data on alcohol consumption are available from the National Drug Strategy Household Survey from 2001 to 2010, and data on use of cannabis and amphetamines are available from 1998 to 2010.

Alcohol is the most commonly used and abused substance in the Australian community, and is a major cause of death, injury and illness. Figure 52 profiles 'risky drinking' of alcohol by young people. 'Risky drinking' is defined as drinking any amount on a daily basis over the course of the previous year, or drinking at risky levels (i.e., more than four standard drinks on one occasion) at least once per month during that year. The percentage of young people aged 14-29 engaging in risky drinking dropped from 47% in 2001 to 42% in 2010. In each year, the proportion of 'risky drinkers' was higher among 20-29 year olds than among 14-19 year olds.

Cannabis is the most commonly used illicit drug in the community, across all age groups. Research evidence is accumulating that cannabis use may precipitate psychotic symptoms or the onset of schizophrenia in people who have a family history or other vulnerability to psychosis. Cannabis use may also exacerbate the symptoms of schizophrenia, but it remains unclear whether or not cannabis causes additional cases of schizophrenia. Cannabis use also poses a moderate risk for later depression, with heavy cannabis use also possibly conferring a small additional risk for suicide.

Figure 53 shows the 12 month prevalence of cannabis use for young people. In 1998, 36% of 14-29 year olds indicated that they had used cannabis in the past 12 months; by 2010 this figure had halved (19%). The drop was greater for 14-19 year olds (35% in 1998 to 16% in 2010) than for 20-29 year olds (37% in 1998 to 21% in 2010). In each group, 2007 was the lowest prevalence year.

Growth in the use of methamphetamines in the 1990s has been associated with a range of mental health and related problems. Symptoms of psychosis are one of the particularly troubling consequences of methamphetamine use and dependent methamphetamine users also suffer from a range of comorbid mental health problems.

Figure 54 shows the use of amphetamines by young people. As with alcohol use and cannabis use, there is evidence of a downward trend in the use of this class of drugs. In 1998, 10% of 14-29 year olds reported using amphetamines, whereas in 2010 only 4% did so. Again, the relative decline in use was greater for 14-19 year olds (from 6% in 1998 to 2% in 2010) than for 20-29 year olds (from 12% in 1998 to 6% in 2010).

The three substances selected here represent a range of licit and illicit drugs that contribute to mental illness in young people. It is positive to note that the use of all three substances has shown an overall decline over time in young people, although it should be acknowledged that use of ecstasy, not reported here, has increased. Various national programs that have been initiated under the National Drug Strategy may have played a role in this decline. Further targeted efforts are required to ensure that the downward trajectory continues.

Figure 52: Percentage of 14-29 year olds engaging in 'risky drinking' in the past 12 months, 2001-10

Refer to the following table for a text equivalent of Figure 52: Percentage of 14-29 year olds engaging in 'risky drinking' in the past 12 months, 2001-10

Text version of figure 52

2001200420072010
14-19 years
39
36
33
33
20-29 years
50
50
50
46
14-29 years
46
45
44
42
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Figure 53: Percentage of 14-29 year olds using cannabis in the past 12 months, 1998-2010

Refer to the following table for a text equivalent of Figure 53: Percentage of 14-29 year olds using cannabis in the past 12 months, 1998-2010

Text version of figure 53

19982001200420072010
14-19 years
35
25
18
13
16
20-29 years
37
29
26
21
21
14-29 years
36
27
23
18
19
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Figure 54: Percentage of 14-29 year olds using amphetamines in the past 12 months, 1998-2010

Refer to the following table for a text equivalent of Figure 54: Percentage of 14-29 year olds using amphetamines in the past 12 months, 1998-2010

Text version of figure 54

19982001200420072010
14-19 years
5.9
6.2
4.4
1.6
1.6
20-29 years
12.0
11.2
10.7
7.3
5.9
14-29 years
9.9
9.2
8.3
5.2
4.4