["Addiction, Volume 121, Issue 5, Page 1290-1305, May 2026. ", "\nAbstract\n\nBackground and Aims\nThere is significant concern about potential rising harms from gamma‐hydroxybutyrate (GHB) but an absence of studies internationally synthesising data across indicators to identify changes in harms and broader patterns of use. This paper contributes to addressing this gap by measuring national trends in GHB use, harms and treatment in Australia.\n\n\nDesign, setting, and cases\nTriangulation of indicators (2013–2024) from Australian triennial population surveys; annual interviews with cross‐sectional non‐representative samples of people who use illicit stimulants or who inject drugs; and administrative data on GHB‐related hospitalisations, GHB‐related deaths, and treatment episodes where GHB was the principal drug of concern.\n\n\nMeasurements\nAnnual trend data were analysed using Joinpoint regression. Survey data were modelled as the annual percent change in the proportion reporting lifetime, past 12‐month, and past 6‐month use, depending on the survey. Administrative data were modelled as the annual percent change in crude rates per 100 000 population.\n\n\nFindings\nLifetime and past 12‐month GHB use in the general population remained below 1.2% and 0.2% respectively, but the latter increased from 0.07% in 2013 to 0.19% in 2022–2023 (annual percent change [APC] 9.3; 95% confidence interval [CI]: 5.2, 13.2). The percentage of people who use illicit stimulants reporting past 6‐month use increased from 5.7% in 2013 to 7.3% in 2017 (APC 11.6; 95%CI: 0.2, 52.9) and from 5.4% in 2019 to 11.5% in 2024 (APC 17.8; 95%CI: 5.9, 41.1). The proportion of people who inject drugs reporting use varied between 7.2% and 17.5% over the short period studied (2020–2024). There were statistically significant increases in GHB‐related hospitalisations from 5.3 in 2012–13 to 19.1 per 100 000 people in 2022–23 (APC 19.0; 95%CI: 11.9, 31.1) and GHB‐related deaths from 0.02 in 2013 to 0.24 per 100 000 people in 2022 (APC 36.5; 95%CI: 27.2, 58.1). Treatment episodes also increased across the period, from 0.07 in 2012–13 to 6.0 episodes per 100 000 people in 2020–21 (APC 97.3; 95%CI: 83.5, 830.9), with no subsequent statistically significant change (8.4 per 100 000 people in 2022–23).\n\n\nConclusions\nGamma‐hydroxybutyrate use, harms and treatment engagement increased in Australia from 2013 to 2024. These findings highlight a need to implement acceptable, tailored prevention and harm reduction strategies for key populations, and implement stronger monitoring efforts nationally and internationally.\n\n"]