Updated

Stopping marijuana use can produce withdrawal symptoms that rival those of nicotine withdrawal, according to a small study published in the journal Drug and Alcohol Dependence.

The study, which looked at 12 adults who were heavy users of marijuana and cigarettes, found that, similar to nicotine withdrawal, quitting marijuana caused symptoms such as irritability, anxiety, sleep problems and difficulty concentrating.

"Marijuana is not as innocuous as some people would lead you to believe," said lead researcher Ryan Vandrey, an assistant professor of psychiatry at Johns Hopkins University School of Medicine in Baltimore.

It's wasn't clear from the study whether withdrawal symptoms actually prevented people from quitting marijuana use.

For the study, researchers asked participants to go through three separate five-day periods of abstinence — one in which they stopped using tobacco, one in which they got off the pot and one in which they quit both.

Click here for the study