VIENNA, Feb. 27 (Xinhua) -- The United Nations (UN) on Thursday called for increased focus on improving substance use prevention and treatment services for young people.

Substance use and associated health consequences are highest among young people, with cannabis being the most widely used substance, according to the 2019 Annual Report of the International Narcotics Control Board (INCB), the UN body for enforcing international drug treaties, published Thursday.

"Of internationally controlled substances, cannabis continues to play the most prominent role among both adolescents and adults," said the INCB President Cornelis de Joncheere launching the report in the Austrian capital.

He also raised the concern over the situation in some countries that "have moved to permit the use of controlled substances, namely cannabis, for non-medical use contrary to the provisions of and their obligations under the drug control treaties."

The INCB annual report also highlighted that the use of alcohol and tobacco by children and adolescents is closely linked to the use of psychoactive substances, a term applied to chemical substances that change a person's mental state by affecting the way the brain and nervous system works.

"Often, the use of alcohol and tobacco precedes the use of cannabis and other controlled substances," according to the report.

It urged governments to improve services using evidence-based prevention and treatment interventions for young people, including strict enforcement of regulations to limit access to medications with psychoactive qualities and reduce accessibility to tobacco, alcohol and cannabis for children and adolescents.