Methamphetamine use in Melbourne was increasing before the first lockdown in 2020 and decreased after it ended. During the second lockdown, methamphetamine trends remained steady before rising steeply after restrictions lifted. Cocaine use stayed steady for most of 2020 and increased after the second lockdown. MDMA use decreased after the first lockdown and remained low through 2020 and 2021. In 2021, stimulant use was less variable and less tied to COVID-19 restrictions than in 2020. The findings show how lockdown periods and social restrictions affected illicit stimulant consumption in one of the world's most locked-down cities.
Methamphetamine use in Hanoi, Vietnam, declined significantly from a peak of 359.2 to 125.6 mg/day/1000 people between 2018 and 2023, while ketamine use rose from 149.7 to 465.9 mg/day/1000 people, becoming the most commonly used illicit drug. Cocaine and heroin remained low, and MDMA was stable. After COVID-19 restrictions eased, cocaine and codeine consumption showed statistically significant declines, whereas ketamine and heroin increased slightly but not significantly. Wastewater analysis of a canal serving over 430,000 people reveals a dynamic drug market shifting toward synthetic substances, with ketamine overtaking methamphetamine as the most used drug by end of 2022.