A pair of new studies has revealed that marijuana use could lead to abuse of other drugs and alcohol. Experts said that these risks need to be considered not only by doctors and patients but by policy makers as well particularly in states where marijuana is legalized for recreational or medical use.
For the first study, which was published in the journal Drug and Alcohol Dependence, the results showed that adults who smoke marijuana have five times increased odds of developing alcohol use disorder (AUD) compared with their counterparts who do not smoke.
By looking at the data of more than 27,000 adults, researchers found that the participants who did not have AUD but reported using cannabis during the first survey were 5.4 times more likely to have an AUD three years later.
The participants who already battle with an alcohol use disorder and were using marijuana were also found to aggravate their dependence on alcohol.
"Among adults with no history of AUD, cannabis use at Wave 1 was associated with increased incidence of an AUD three years later relative to no cannabis use," study researcher Renee Goodwin, from Columbia University, and colleagues wrote. "Among adults with a history of AUD, cannabis use at Wave 1 was associated with increased likelihood of AUD persistence three years later relative to no cannabis use."
The second study, which was published in JAMA Psychiatry and involved more than 34,000 subjects, revealed that participants who used cannabis during the first survey were about six times as likely to suffer from substance use disorder after three years.
Researchers also found an increased risk for drug use disorders and nicotine dependence among pot smokers.
Although the study authors said that their findings do not establish a cause and effect relationship between pot use and substance abuse, they noted that there may be an overlap in brain circuitry that influence drug use and dependence.
"Our study indicates that cannabis use is associated with increased prevalence and incidence of substance use disorders," Carlos Blanco, from the National Institute on Drug Abuse, and colleagues wrote. "These adverse psychiatric outcomes should be taken under careful consideration in clinical care and policy planning."