Trends and psychosocial correlates of same day polysubstance use among people who inject drugs in Australia, 2012-2022

Olivia Price; Rachel Sutherland; Nicola Man; Raimondo Bruno; Paul Dietze; Caroline Salom; Jane Akhurst; Amy Peacock

doi:10.1016/j.drugpo.2023.104150

Trends and psychosocial correlates of same day polysubstance use among people who inject drugs in Australia, 2012-2022

Int J Drug Policy. 2023 Aug 2:104150. doi: 10.1016/j.drugpo.2023.104150. Online ahead of print.

Authors

Olivia Price¹, Rachel Sutherland², Nicola Man², Raimondo Bruno³, Paul Dietze⁴, Caroline Salom⁵, Jane Akhurst², Amy Peacock³

Affiliations

¹ National Drug and Alcohol Research Centre, UNSW Sydney, Sydney, NSW, Australia. Electronic address: o.price@unsw.edu.au.
² National Drug and Alcohol Research Centre, UNSW Sydney, Sydney, NSW, Australia.
³ National Drug and Alcohol Research Centre, UNSW Sydney, Sydney, NSW, Australia; School of Psychological Sciences, University of Tasmania, Hobart, Australia.
⁴ Behaviours and Health Risks, Burnet Institute, Melbourne, Australia; National Drug Research Institute, Curtin University, Melbourne, Australia; School of Public Health and Preventive Medicine, Monash University, Melbourne Australia.
⁵ National Drug and Alcohol Research Centre, UNSW Sydney, Sydney, NSW, Australia; Institute for Social Science Research, The University of Queensland, Brisbane, Australia.

PMID: 37541925
DOI: 10.1016/j.drugpo.2023.104150

Abstract

Background: Polysubstance use is associated with negative health and social outcomes among people who inject drugs. We aimed to describe trends in polysubstance use and identify psychosocial correlates and associated drug use risk behaviours. We defined polysubstance use as intentional same day use of more than one of three drug classes: opioids, other non-opioid depressants (hereafter 'depressants'), and stimulants.

Methods: We used 10 years (2012-2022, excluding 2020) of data from annual surveys in Australian capital cities with people who inject drugs (N=5657) to construct five mutually exclusive polysubstance use profiles: opioid-depressant, opioid-stimulant, stimulant-depressant, opioid-stimulant-depressant, and single drug class use. We examined time trends using the Mann Kendall test and identified correlates using multinomial logistic regression.

Results: Same day polysubstance use was relatively common among this sample (43.6%). Opioid-depressant use was the most frequent polysubstance use profile, but this decreased over the study period (32.6% to 13.3%, p<0.001). This aligned with observed decreases in use of pharmaceutical opioids (p<0.001), opioid agonist treatment (p=0.007), and benzodiazepines (p=0.001). There was no evidence for any trend in the other polysubstance use profiles, although single drug class use increased (51.9% to 64.7%, p=0.031). The different polysubstance use profiles were variously associated with psychosocial factors, including unstable housing and very high psychological distress, and other drug use risk behaviours, including non-fatal overdose, receptive and/or distributive needle sharing, and reusing one's own needles.

Conclusion: Same day polysubstance use has remained relatively common among this sample over time, although the typology has changed. Collectively, our findings point to diverse drug use patterns among people who inject drugs and reiterate the need for a range of harm reduction, treatment, and support options.

Keywords: Injecting drug use; Opioids; Polysubstance use; Psychosocial risk factors; Stimulants.