Does Marijuana Cause Psychosis?

A study of past research funded by the British government purports to show that marijuana use causes psychosis . However, the researchers themselves say it's possible that their results may not be entirely accurate. What are we to believe?

LONDON - Using marijuana seems to increase the chance of becoming psychotic, researchers report in an analysis of past research that reignites the issue of whether pot is dangerous.

The new review suggests that even infrequent use could raise the small but real risk of this serious mental illness by 40 percent.

Sound ominous? Get this:

“The available evidence now suggests that cannabis is not as harmless as many people think,” said Dr. Stanley Zammit, one of the study’s authors and a lecturer in the department of psychological medicine at Cardiff University.

The researchers said they couldn’t prove that marijuana use itself increases the risk of psychosis, a category of several disorders with schizophrenia being the most commonly known.

There could be something else about marijuana users, “like their tendency to use other drugs or certain personality traits, that could be causing the psychoses,” Zammit said.

Like Mark Twain once said, "There are three kinds of lies; lies, damn lies, and statistics."