David L. Nathan: Don't fall for warnings about pot

• By David L. Nathan

  
  

  It’s no secret. Most Americans now favor making marijuana legal. The national numbers are similar to those in Rhode Island, where a recent poll showed that 57 percent of Rhode Island residents support legalization. Prohibitionists are rapidly losing the debate because the facts are against them. Nonetheless, they continue to repeat three arguments that have been thoroughly debunked by objective scientific research.

   First, opponents of legalization claim that marijuana is a "gateway" to hard drugs like cocaine and heroin. Numerous studies over the past 70 years — including one commissioned by the White House — have discredited this hypothesis. Yet prohibitionists continue to claim that marijuana use leads to later use of heroin and other dangerous drugs. Roughly half of all American adults have tried marijuana. If marijuana is a "gateway drug" as opponents claim, why do we find that only 2 percent of Americans have ever tried heroin?

   Second, prohibitionists commonly argue that making marijuana legal will lead to carnage on the highways. That has not been the case in Colorado, where the number of traffic fatalities in 2014 was on par with those of previous years. Furthermore, several studies have shown that marijuana causes far less driving impairment than alcohol intoxication.

  Research released in February from the National Highway Traffic Safety Administration found that a blood alcohol concentration of 0.05 or above increases the odds of a fatal car accident sevenfold. The same study found that after adjusting for age, gender, race, and alcohol use, drivers who used marijuana were no more likely to be in a fatal car accident than drivers who had not used any drugs or alcohol prior to driving.

   Third — and most importantly — opponents of legalization have insisted that marijuana use will skyrocket among teens when it is made legal for adults, but few of them acknowledge that marijuana is already widely available and used by adolescents under prohibition. Since the 1970s, the University of Michigan’s Monitoring the Future Study has consistently found that 80 to 90 percent of high school seniors report that marijuana is “fairly easy” or “very easy” to obtain.

   While remaining legal for adults, alcohol and cigarette use among teens has steadily declined to historic lows in recent decades. But teen use of marijuana has risen despite its prohibition. In fact, marijuana prohibition could be increasing teen use. Alcohol and tobacco retailers check IDs and refuse to sell to minors, but unscrupulous street corner drug dealers will sell marijuana — along with hard drugs — to minors.

   Although prohibitionists claim that making marijuana legal for adults “sends the wrong message to kids,” teen marijuana use in Colorado has remained level since legalization. The fact that prohibitionists’ dire prediction did not materialize may explain why polls show more Colorado voters now support legal marijuana than did in 2012.