"Between 2005 and 2009, the number of regular opium and heroin users increased by 53 percent and 140 percent respectively," the report said.
The Afghanistan Drug Report 2012 also said the drug users were financially burdened by their addictions with total spending on drug use averaging $300 million annually in the country.
The report highlighted key achievements in the development of institutional and policy frameworks in response to illicit drugs in the war-torn country.
At the same time, the report showed that "the cultivation, trafficking and use of illicit drugs remain critical challenges for Afghanistan, resulting in significant negative social, economic and political impacts".
"Also, the number of drug treatment centres increased by 58 percent between 2009 and 2012 but overall capacity remains low, covering only 5.9 percent of the opium and heroin users in the country," it said.
Afghanistan remains the main producer of opium as about 90 percent of the world's opium, the raw material used in manufacturing heroin, is produced in this country.