Research published by the Federal Center for Health Education (BZgA) on Tuesday found that marijuana use by Germans up to the age of 25 had risen by more than one third over the past six years.

For the study, a total of 7,000 teenagers and young adults were interviewed between May and August 2014. Around 18 percent between the ages of 18 and 25 said they had used marijuana in the past 12 months. That's up from the 11.5 percent saying the same in 2008.

More than a third of respondents said they had tried cannabis at least once, while around 5 percent described themselves as regular users. In the younger 12-17-year-old age bracket, one in 10 admitted to trying the drug.

According to the data, young men were far more likely to consume cannabis than women. In 2008, one in seven young men said they were consumers, compared to one in four in 2014. Over the same period consumption among young women also increased from 8 percent to 11 percent.

BZgA director Heidrun Thaiss said the study pointed to a "worrying development," warning that increasing cannabis use can affect individuals' brain performance.

"Comprehensive prevention programs are essential to counteract this development and to convince young people not to begin using cannabis in the first place," she said.

Federal Drug Commissioner Marlene Mortler blamed the increase on advocates of marijuana legalization, saying they had "trivialized the health risks."

Currently the possession, cultivation and sale of marijuana is outlawed in Germany. However most federal states won't prosecute people caught with up to six grams. Germany has been making small steps towards allowing more people legal access to the drug for medical reasons.

nm/msh (AFP, dpa)