Age of initiation
In 2019, the average age at which people first tried any illicit drug was 19.9 years, the oldest it has been in 18 years. This figure remained relatively stable since 2016 (19.8 years), but has increased overall since 2001 (18.6 years) (Table S3.48) (AIHW 2020b). The average age of initiation has increased since 2001 for a range of drugs including cannabis, cocaine, and inhalants (AIHW 2020b).
Cannabis
Estimates from the NDSHS show that people aged 18–24 continue to be the most likely age group to use cannabis, and cannabis is the most widely used drug among this age group (AIHW 2020b). In 2019, one-quarter (25%) of people in this age group had used cannabis in the past 12 months, compared with 11.6% of people aged 14 and over (Table S3.45). However, recent use of cannabis has been declining among this cohort since 2001 (32%), but remained stable from 2016 (24%) to 2019 (AIHW 2020b).
Use of cannabis is relatively less common among 14–17 year olds, with 8.2% of people in this age group having recently used cannabis in 2019 (AIHW 2020b) (Table S3.45). This represents a decrease from 21% in 2001, and a slight increase from 7.9% in 2016.
The Australian Secondary Students’ Alcohol and Drug (ASSAD) survey reported that:
- in 2017, 8% of students aged 12–17 had used cannabis in the month before the survey and 16% reported using cannabis in their lifetime, making cannabis the most commonly used drug in this cohort (Table S2.41)
- there were no significant differences between 2011 and 2017 in the proportion of students aged 12–17 who reported lifetime and past month use of cannabis
- however, there was a significant increase in the proportion of females aged 16–17 who had used cannabis in the past month (10% in 2011 compared with 14% in 2017) (Table S2.40).
Meth/amphetamine and other stimulants
Use of meth/amphetamine among younger people has declined over time. Estimates from the 2019 NDSHS showed that:
- recent use of meth/amphetamine among young adults aged 18–24 has declined from 13.2% in 2001 to 2.3% in 2019. This pattern was consistent for both males (15.0% to 3.5%) and females (11.3% to 0.8%), although the 2019 estimates for both males and females have a relative standard error of 25% to 50% and should be interpreted with caution
- the proportion of people aged 18–24 who have recently used meth/amphetamine remained stable from 2016 (2.3%) to 2019 (AIHW 2020b) (Table S3.47).
By contrast, recent use of cocaine and ecstasy has increased since 2016, though this has fluctuated over time. NDSHS estimates suggest that among people aged 18–24:
- use of cocaine increased from 2016 (5.1%) to 2019 (10.8%), with significant increases for both males (from 5.7% to 13.1%) and females (4.5% to 8.0%) (Table S2.47)
- use of ecstasy has been fluctuating since 2001 (11.7%), but significantly increased from 2016 (8.0%) to 2019 (10.8%). This was driven by an increase in recent use among males (from 7.4% in 2016 to 12.6% in 2019) (AIHW 2020b) (Table S2.46).
The use of stimulants among younger people aged 17 and under appears to be less common, with findings from the ASSAD survey revealing that most secondary school students aged 12–17 had never tried amphetamines (98%), cocaine (98%) or ecstasy (95%) (Guerin & White 2020).
Other drugs
Other drugs that are used by young people include inhalants, hallucinogens, ketamine, new and emerging psychoactive substances, and tranquilisers and other pharmaceuticals for non-medical purposes (AIHW 2020b, Guerin & White 2020). The 2017 ASSAD survey showed that, among students aged 12–17:
- around 1 in 5 (19%) students had ever used tranquilisers for a non-medical reason, but only 5% had used them in the past month (Table 2.53) (Guerin & White 2020). This is higher than 2019 NDSHS estimates (1.3% for lifetime use among people aged 14–17, and 0.7% for use in the past 12 months), though these estimates have relative standard errors of 25% to 50% and should be used with caution (AIHW 2020b).
- 18% of students had deliberately sniffed inhalants at least once in their lifetime, with 7% reporting doing so in the past month (Table 2.53). 13% had used inhalants in the past year—of those, most (43%) had tried them once or twice however almost 1 in 5 (19%) had done so more than 10 times in the past year (Guerin & White 2020).
- the majority of students (97%) reported they had never used synthetic cannabis or any new synthetic drug in the last 12 months (Guerin & White 2020) (Table S2.57). This is supported by findings from the 2019 NDSHS (AIHW 2020b).
Additionally, the NDSHS has showed that use of certain drugs among younger people aged 18–24 has fluctuated or increased over time (AIHW 2020b). Specifically:
- non-medical use of pharmaceuticals in the past 12 months increased from 4.6% in 2007 to 6.3% in 2019, while use of ketamine rose from 1.6% in 2016 to 4.1% in 2019
- the proportion of people who have recently used hallucinogens has fluctuated over time, with 5.2% of those aged 18–24 reporting recent use in 2019 (AIHW 2020b).
Geographic trends
Data from the 2019 NDSHS showed that the proportion of 18–24 year olds who reported recent illicit drug use has fluctuated over time and within jurisdictions (Table S3.44; Figure YOUNGER6).