How has the proportion of cannabis treatment episodes in Australia changed over time compared to other drugs?

The proportion of treatment episodes in Australia for which cannabis is the principal drug of concern has remained relatively stable over the past decade, but with a slight downward trend since 2014-15.

Alcohol has consistently been the most common principal drug of concern in the past decade. Cannabis was the second most common principal drug of concern between 2008-09 and 2014-15. In 2015-16 amphetamines and cannabis were the equal second most common principal drug of concern. Since 2016-17 cannabis has been the third most common principal drug of concern (after amphetamines).

In Australia in 2008-09, alcohol was the principal drug of concern in 46% of treatment episodes; cannabis in 23%; heroin in 10%; amphetamines in 9%; and other drugs in 12%. In Australia in 2009-10, alcohol was the principal drug of concern in 48% of treatment episodes; cannabis in 23%; heroin in 10%; amphetamines in 7%; and other drugs in 12%. In Australia in 2010-11, alcohol was the principal drug of concern in 47% of treatment episodes; cannabis in 22%; heroin in 9%; amphetamines in 9%; and other drugs in 13%. In Australia in 2011-12, alcohol was the principal drug of concern in 46% of treatment episodes; cannabis in 22%; heroin in 9%; amphetamines in 11%; and other drugs in 12%. In Australia in 2012-13, alcohol was the principal drug of concern in 41% of treatment episodes; cannabis in 24%; heroin in 8%; amphetamines in 14%; and other drugs in 13%. In Australia in 2013-14, alcohol was the principal drug of concern in 40% of treatment episodes; cannabis in 24%; heroin in 7%; amphetamines in 17%; and other drugs in 12%. In Australia in 2014-15, alcohol was the principal drug of concern in 38% of treatment episodes; cannabis in 24%; heroin in 6%; amphetamines in 20%; and other drugs in 12%. In Australia in 2015-16, alcohol was the principal drug of concern in 32% of treatment episodes; cannabis in 23%; heroin in 6%; amphetamines in 23%; and other drugs in 17%. In Australia in 2016-17, alcohol was the principal drug of concern in 32% of treatment episodes; cannabis in 22%; heroin in 5%; amphetamines in 26%; and other drugs in 15%. In Australia in 2017-18, alcohol was the principal drug of concern in 35% of treatment episodes; cannabis in 22%; heroin in 6%; amphetamines in 27%; and other drugs in 11%.

Source: Australian Institute of Health and Welfare (AIHW). Alcohol and Other Drug Treatment Services in Australia 2017-18.

Please note: Percentages may not tally to 100% due to rounding.

Principal Drug of Concern: The main substance that leads an individual to seek treatment from an alcohol and drug treatment agency (as stated by the individual).

Treatment Episode: A period of contact between a client and a treatment provider. Only ‘closed’ treatment episodes are included in the data used here. An episode is closed if there is a change in the principal drug of concern, main treatment, or service delivery setting; if the treatment ends; or if the patient is imprisoned or dies.