Tweets supporting the legalization of marijuana are reaching hundreds of thousands of teens and young adults daily.

Researchers at Washington University School of Medicine in St. Louis have found that "Twitterverse" is a pot-friendly place. In a one-month period in early 2014, more than 7 million tweets referenced marijuana, with 15 times as many pro-pot tweets sent as anti-pot.

Most of those sending and receiving pot tweets were younger than 25, with many in their teens, a demographic group at increased risk for developing marijuana dependence and other drug-related problems.

"It's a concern because frequent marijuana use can affect brain structures and interfere with cognitive function, emotional development and academic performance," Patricia A. Cavazos-Rehg, first author of the study, said in a statement. "The younger people are when they begin using marijuana, the more likely they are to become dependent. A lot of young people will phase out of marijuana use as they get older, but unfortunately, we're not good at predicting who those individuals are."

For the study, researchers analyzed every marijuana-related Twitter message sent from Feb. 5 to March 5, 2014. They conducted computer searches using search terms such as "joint," "blunt," "weed," "stoner" and "bong" to discover more than 7.6 million tweets related to pot.

They also focused their analysis on Twitter accounts with more than 775 followers as well as accounts with Klout scores of 44 and above. A Klout score measures social media influence on a scale of 1-100.

Examining a random sample of almost 7,000 tweets from these accounts, the researchers found that 77 percent were pro marijuana, 5 percent were against pot, and 18 percent were neutral. People tweeting pro-marijuana messages had a total of more than 50 million Twitter followers, about 12 times more than those tweeting anti-marijuana messages, the researchers noted.

Pro-pot tweets most commonly were aimed at encouraging the use of marijuana and its legalization and made claims about the drug's health benefits. Ten percent of the pro-marijuana tweets were sent by people who said they were currently using pot or high.

Anti-marijuana tweets often stated that the drug's users were losers or unproductive or that marijuana use is unattractive. Those whose tweets were anti-pot also stressed that the drug was harmful or that the person tweeting was against legalization.

"Although we can't yet link pro-pot tweets to actual drug use, we should be worried because many people are receiving these messages are at an age when they are most likely to experiment with drugs and develop problems with substance use," Cavazos-Rehg said.

The findings are detailed in the Journal of Adolescent Health.