In an op-ed piece sure to draw heavy readership in the Northwest, the author and former New York Times pharmaceutical reporter Alex Berenson this weekend raised serious questions about the impact of legal recreational marijuana.

Berenson, who left the Times in 2010 to write spy novels, has been working on a new non-fiction book called Tell Your Children: The Truth About Marijuana, Mental Illness and Violence, writes that advocates for cannabis legalization have successfully shifted the national conversation away from potential risks of the drug.

"The scientific literature around the drug is far more negative than it was 20 years ago," Berenson writes. "Yet the change in the scientific consensus has gone unnoticed. Americans in general are far more likely to believe the drug is safe, and even medically beneficial, than they once were. As a result, support for legalization has doubled since 1999."

As Oregonians know, the cannabis for sale today is much more potent than the product black market dealers sold in previous decades.

Berenson, while noting he is not a prohibitionist, draws parallels between the claims cannabis advocates make today with the claims advocates for prescription opioids made in the past. And without claiming causation, Berenson notes that the incidence of serious mental illness among Americans 18 to 25 years old—the demographic most likely to use cannabis—is on the rise. So is crime, although, again, Berenson notes a coincidence without claiming correlation.

"Before recreational legalization began in 2014, advocates promised that it would reduce violent crime," Berenson writes. "But the first four states to legalize—Alaska, Colorado, Oregon and Washington—have seen sharp increases in murders and aggravated assaults since 2014, according to reports from the Federal Bureau of Investigation. Police reports and news articles show a clear link to cannabis in many cases."

Violent crime, including murder, has risen across Oregon over the past four years, but remains far below its 1990s rates. Oregon violent crime rate ranks 36th in the nation.