By David L. Nathan

Throughout my career in medicine, two principles have guided my work: to do no harm and to base all decisions on empirical evidence.

Both tenets have led me to vigorously support legalization, taxation, and regulation of marijuana for use by adults 21 and older.

Recently, state Sen. Raymond Lesniak (D-Union) promoted some misleading conclusions about the available data on marijuana legalization. Purportedly scientific studies used to justify the status quo can be manipulated to "prove" a conclusion unsupported by evidence. I want to set the record straight.

Before digging into the science, let's consider the "War on Marijuana" and public health. New Jersey made 24,689 marijuana possession arrests in 2014. One arrest can cost individuals their jobs, homes, eligibility for public benefits like state scholarships, and even custody of children.

This is a public health disaster, and all for a plant the last 24 years of U.S. presidents have admitted using.

While an important step toward legalization, decriminalization alone will not right the wrongs of prohibition. The only avenue to purchase marijuana would still be through illegal channels, where dealers can sell harder or potentially adulterated substances to any buyer, including children.

A better way to combat the harms of the illegal drug trade is through a legal, safe, and responsibly regulated system.

As a physician and a father, I have deep concerns about marijuana's impact on developing brains. That's why I favor a regulated market, rather than our current illegal market, to limit underage access to the drug.

Based on the facts, many physicians, including the prestigious roster of Doctors for Cannabis Regulation, have come to understand that cannabis use should be controlled through legalization for adults, evidence-based prevention, education for minors, and close regulation of the industry. Only legalization empowers the government to ensure safe production, testing, labeling, distribution and sale of cannabis. Only legalization will ensure someone is checking ID when marijuana is sold.

We can learn from Colorado, the first state to implement a legalized system, starting January 1, 2014. Even in that limited time, we know legalization has not been the public health disaster some predicted. Marijuana-related public health outcomes have stayed the same or improved since legalization.

Despite claims to the contrary, underage use has not significantly increased in states where marijuana is legal for adults. The newly released 2015 Healthy Kids Colorado Survey reported teens' current and lifetime marijuana use has remained virtually unchanged from 2009, with the percentage of teen users dropping slightly. Multiple surveys show consistent downward trends in Oregon's teen use. Generally, states with high teen use pre-legalization continue to have it now; states with lower teen use before stay lower.

A frequently cited source for opponents of reform, the anti-reform Rocky Mountain High Intensity Drug Trafficking Area (RMHIDTA) task force, is known for cherry-picking data to intentionally paint an inaccurate, doomsday picture of marijuana's impact. The task force claims crime increased in Colorado after legalization. The facts reveal the opposite. The Colorado Bureau of Investigation cites a 4 percent decrease in overall crime from 2013 to 2014. That post-legalization dip represented the largest single-year drop since 2008.

Similarly, RMHIDTA's statistics showing an uptick in marijuana-related emergency room admissions may say more about people being less afraid to tell an ER doctor about using marijuana than any actual increase in marijuana-related emergencies. Even more damning, the authors of the RMHIDTA-cited study specifically warned that reporting was "incomplete" and should not lead to "inferences concerning trends." RMHIDTA disregarded the advisory, presenting it as fact.

While course correction for new policy is always important, let's face facts: marijuana legalization has proven wrong those who predicted catastrophe.

Like doctors, increasing numbers of Americans and New Jerseyans support legalization for adults. In 2015, a Rutgers-Eagleton poll found that 58 percent of New Jerseyans held that position, up nine points from 2014. For adults, the harms of keeping marijuana illegal vastly outweigh the harms of using it.

Having weighed the evidence and studied the science, my colleagues and I believe that we can limit the health risks of marijuana and eliminate the harms of its prohibition through legalization, taxation, and smart regulation.

David L. Nathan, MD, is the Princeton-based founder and board president of Doctors for Cannabis Regulation, which is a member of New Jersey United for Marijuana Reform's steering committee. He is a distinguished fellow of the American Psychiatric Association and clinical associate professor of psychiatry at Rutgers Robert Wood Johnson Medical School.

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