I'm missing something here. I don't see how you get from malt liquor, marijuana use, and alcohol problems later in life are correlated to the conclusion that malt liquor causes marijuana use and alcoholism. I didn't read the study so maybe there's some way to tease causality out of the data, but why should we be surprised that someone who, when given a choice, chooses a high alcohol content beverage, and one that has a relatively low per dollar alcohol cost (see bottom of table 1 for responses to "because it is cheap" and "to get drunk quickly," the two most often cited reasons for choosing malt liquor), would also tend to use other drugs at a higher than average rate and be at a higher risk for alcoholism later in life?:
Malt liquor linked to marijuana use among young adults, EurakAlert: Drinking malt liquor -- the cheap, high-alcohol beverage often marketed to teens -- may put young adults at increased risk for alcohol problems and use of illicit drugs, particularly marijuana, according to a new study of malt liquor drinkers and marijuana use by scientists at the University at Buffalo’s Research Institute on Addictions (RIA).
“In our study of young adults who regularly drink malt liquor,” reports lead researcher R. Lorraine Collins, senior research scientist at RIA, “we found that malt liquor use is significantly related to reports of alcohol problems, problems specific to the use of malt liquor and to marijuana use above and beyond typical alcohol use.” ...
The study consisted of 639 young adults (456 men) of approximately 23 years of age who regularly consume 40 ounces or more of malt liquor per week. ... The participants were heavy drinkers, averaging 30 alcoholic drinks -- including 17 malt liquor drinks -- per week.
In addition to malt liquor use, marijuana was the illicit drug of choice, with 46 percent reporting simultaneous use of malt liquor and marijuana. Individuals who used malt liquor and marijuana together smoked 19 marijuana joints, on average, during a typical week, whereas those who did not use the two together smoked two marijuana joints, on average, during a typical week. Very few participants reported regular use of other illicit drugs.
For those individuals who use malt liquor and marijuana simultaneously, the study showed that they first drank alcohol at a younger age (between 13 and 14 years) and reported more substance use (particularly marijuana use) and more alcohol-related problems than those who did not use both malt liquor and marijuana together. Sixty-one percent of the participants reported that they consumed one to two 40-ounce containers of malt liquor on a typical drinking occasion. Given malt liquor’s higher alcohol content -- 6-11 percent alcohol -- this level of intake could translate into 3.5 (one 40-oz. bottle at 6 percent) to 14 (two 40-oz. bottles at 11 percent) standard drinks.
“These results suggest that regular consumption of malt liquor, beyond that associated with typical alcohol use, may place young adults at increased risk for substance abuse problems,” Collins says. “Although many of these young people may not yet meet diagnostic criteria for alcohol dependence, there is clearly a need for prevention strategies targeted to ... excessive drinking of malt liquor.”
I have a hard time believing that stopping people from drinking malt liquor in and of itself will do much, if anything, to prevent addiction problems. If malt liquor disappears, another drink will take its place. The focus needs to be on changing the behavior and thought processes that lead to excessive drinking and drug use, not on eliminating a particular type of drink.