A man lights a marijuana joint at Dundas Square in Toronto April 20, 2007. Marijuana smokers gather on April 20 every year to publicly push for its legalization. (Xinhua/Reuters Photo)

    BEIJING, July 27 (Xinhuanet) -- Using marijuana seems to increase the risk of a psychotic illness such as schizophrenia, according to a stuy in media reports Friday. 

    The researchers found that marijuana users had a 41 percent increased chance of developing psychosis marked by symptoms of hallucinations or delusions later in life than those who never used the drug. The risk rose with heavier consumption.

    Marijuana is one the most commonly used illegal substances in many countries with up to 20 percent of young people in places like Britain reporting either some use or heavy use, British researchers said, citing government statistics.

    Many consider it on par with alcohol or tobacco but the results show marijuana poses a danger many smokers underestimate, said Stanley Zammit, a psychiatrist at Cardiff University and the University of Bristol in UK, who worked on the study.

    "If you compare other substances like alcohol or tobacco it may not be as harmful, but what we are saying is neither is it completely safe," Zammit said in a telephone interview.

    Other findings have highlighted the link between marijuana use and the risk of schizophrenia-like symptoms such as paranoia, hearing voices and seeing things that are not there.

    (Agencies)