The total number of reported drug abusers fell 8% year-on-year to 7,081 in the first three quarters of the year, while the number of reported drug abusers aged under 21 dropped 17% to 552.
The latest figures from the Central Registry of Drug Abuse show drug use in Hong Kong continued to decline, particularly among young adults.
The number of new drug users, at 1,609, fell 2% on the same period in 2014, while the number of under-21s becoming addicted to drugs fell 16% to 321.
Heroin is still the most commonly abused drug in Hong Kong with number of abusers down 7%, while methamphetamine surpassed ketamine as the most common psychotropic substance abused, with abusers increasing by 2%.
Action Committee Against Narcotics Chairman Dr Ben Cheung said today the hidden drug abuse trend remains a cause for concern, adding that early identification and assistance are the best means of preventing any drug from inflicting irreversible harm to a person.
Commissioner for Narcotics Erika Hui said the Government will continue to raise awareness of the drug problem.